Cave Story+ Achievement Guide

  • Author : L-r | BC
  • Time To Complete : Unknown
  • Difficulty : Unknown
  • Online : 0/76
  • Offline : 76/76
  • Missable : Unknown
  • Glitched : Unknown
  • Num Playthroughs : Unknown
Introduction

A detailed guide on how to obtain all 76 achievements in Cave Story+.

Achievement Walkthrough Toggle Toggle Walkthrough
Basic Info
Cave Story+ is probably the best version of Cave Story you can get. It features the same classic game, along with multiple modes and graphic/sound options.

It also has a total of 76 achievements. While some achievements are easy to find, others are not. This guide will tell you how to get every single one of them.

Notice: This guide contains spoilers

Also: Some players have reported that playing the game with a language that is not English may cause some of the achievements to not unlock.

List of unmissable achievements

If you just complete the normal ending, you will always get these achievements:

  • Pea Shooter
  • <3
  • Rabid Mimiga
  • What Are YOU?!?
  • Huge Toad
  • Mimiga Bodyguard
  • Machine Monster
  • Ate A Red Flower
  • Ghost in the Clinic
  • Armored Feline
  • Miserable
  • House Call
  • Muscle, MD.
  • Evil to the Core

Best ending achievements

These achievements are obtained while saving Curly and getting the best ending
  • Tow Me A Rope
  • What A Fun Guy!
  • I’ve Got Your Back
  • Return the Favor
  • Rock Bustin’
  • Heart of the Island
  • Big Fish
  • Heavy Medal
  • Swollen Mech
  • Hate Made Flesh
  • Curse Broken
Throughout this guide I will constantly mention about the “save Curly quest.” If you are confused on what I mean by this, please refer to this guide that explains how to get the best ending. http://steamcommunity.com/sharedfiles/filedetails/?id=118172375
 
Credits
I hope that this guide helps anyone who may have had trouble discovering some of these achievements since most of them are hidden. So far this is my biggest guide, and it was not easy to make (had to replay the game a few times to get some screenshots). Aside from patting myself on the back for actually creating this big guide, I would like to thank the following:

Daisuke “Pixel” Amaya, for creating Cave Story.
Nicalis, for updating Cave Story multiple times (such as Cave Story 3D and Cave Story+).
Steam user MasterLuigi452, for his brilliant Sanctuary guide that I mentioned and for fixing a few errors regarding difficulty differences.


Achievement Guide
Pea Shooter Pea Shooter
Obtained the Polar Star!

The first achievement you’ll get, which is impossible to miss. When you start the game, exit the room that you’re in and head left, then fall, then head right. Enter the room and open the chest to get the polar star.

Hidden Achievement
A Gift from Santa A Gift from Santa
Hidden achievement descriptions are missing by default. Why is it missing?

In the Bushlands, you’ll find a key on the ground. Grab it, and head back to the very start of the area and give it to the mimiga named Santa. After that, go into his house, talk to him, and he’ll give you the fireball (and you’ll get the achievement).

Mr. Clean Mr. Clean
Obtained the Bubbline!

Get some jellyfish juice from the big jellyfish in the Bushlands, then go back to Mimiga Village. Go into the main hall (the big house next to the graveyard) and use the juice on the fireplace. You’ll then find the bubbline.

Magic Missile Magic Missile
Obtained the Missile Launcher!

The missile launcher is located in a chest in the egg observation room in the Egg Corridor (the room with the elevator to the left).

Hidden Achievement
Super, thanks for asking! Super, thanks for asking!
Hidden achievement descriptions are missing by default. Why is it missing?

After you beat Monster X (the robot cat) in the Labyrinth, head right, and you’ll see Professor Booster fall down. Either hop across to the room to the right or talk to him and use the booster he gives you to fly into the room. I highly suggest jumping over because falling down will prevent you from getting the best ending as well as other achievements. After a small talk with Curly, you’ll have to fight Balrog again. When you beat him, open the chest and you’ll get the super missiles.

Girly Gun Girly Gun
Obtained the Machine Gun!

NOTICE: By obtaining the machine gun, you will not be able to get a few more weapons which unlock achievements

When you beat Curly, you can talk to her anytime to trade your polar star for her machine gun (though you’ll be unavailable to do this later on).

Hidden Achievement
Cold Hearted Snake Cold Hearted Snake
Hidden achievement descriptions are missing by default. Why is it missing?

Same thing as the Turbocharged! achievement (go to the shop in the Labyrinth), except you must keep your polar star. Talk to the shop keeper and he’ll give you the snake item, but at the cost of your polar star AND your fireball.

Hidden Achievement
Freakin' Laser Beamz Freakin’ Laser Beamz
Hidden achievement descriptions are missing by default. Why is it missing?

When you return to Mimiga Village (whether it be from the Labyrinth or from the Waterway), get back to the area where you first started the game. You’ll have to hop onto the top of the save room and use your booster pack (can be either version, though it’s much easier with v 2.0) so that you’ll land on a flat area with a door. When you enter, you’ll be back at the start of the game. Now just go back to where you got originally got the polar star, talk with the guy, and he’ll upgrade your polar star to the spur.

Hidden Achievement
A Fine Blade A Fine Blade
Hidden achievement descriptions are missing by default. Why is it missing?

When you beat rabid Toroko in the Sandzone, go to King’s body and talk to him. He’ll die, and leave his sword. Grab it to get the achievement.

Hidden Achievement
Ducking Awesome Ducking Awesome
Hidden achievement descriptions are missing by default. Why is it missing?

When you first reach the outer walls, head down and enter the door. Talk to the tiny people, and then head to the graveyard in Mimiga Village. Near the bottom, you’ll find a tiny man walking around (see the Little Man achievement for his exact location). Pick him up, and head back to the home with the tiny people. The person you brought there will give you the option to trade your blade for his nemesis (obtaining it will grant you the achievement). Luckily, you’ll be able to trade it back for your blade if you don’t like it.

Don't Get Lost Don’t Get Lost
Obtained the Map System!

In Mimiga Village, go outside of the save room door and fall down to the right. Land on the platform and then hop onto the platforms to the right. You’ll find the map system in the chest.

Hidden Achievement
Ladies' Man Ladies’ Man
Hidden achievement descriptions are missing by default. Why is it missing?

When you get to the Bushlands, you’ll eventually have to go inside Chaco’s (the purple mimiga) house so you can inspect her fireplace which causes jellyfish to spawn. When you first inspect the fireplace, Chaco will walk to you and explain that you need jellyfish juice to put it out. When she’s done talking, sleep in her bed. When you wake up you’ll have the red lipstick and the achievement.

<3 <3
Obtained the Life Pot!

When you find all of Jenka’s dogs in the Sandzone, Balrog will steal the key and Jenka will talk to you. She’ll give you the life pot when she’s done talking.

Hidden Achievement
Tow Me A Rope Tow Me A Rope
Hidden achievement descriptions are missing by default. Why is it missing?

In the Labyrinth, when you see Professor Booster fall down, hop over to the door to the right, and continue playing (do not follow him). Continue through the level normally until you reach a chamber with the core (the big area with destroyed robots everywhere). When you get to the big area, head to the bottom right of the area and you’ll see something sparkling in the water. Grab it and you’ll get the tow rope (also note that you need this to get the best ending).

Hidden Achievement
Panty Raider Panty Raider
Hidden achievement descriptions are missing by default. Why is it missing?

Go into the house in the Sandzone where you fought Curly, and go into the back room. Hop onto the top left area, and you’ll be able to go through the wall. Then jump up, head to the right, and fall down. Keep pressing down and you’ll eventually open a chest with Curly’s panties. You’ll get the achievement AND unlock Curly mode.

Hidden Achievement
Supa Star! Supa Star!
Hidden achievement descriptions are missing by default. Why is it missing?

Same thing with Turbocharged and the Cold Hearted Snake achievements, although this time you need the spur and the booster pack v 2.0. When you get the spur, head back to the Labyrinth shop, talk to the same bug, and he’ll give you the whimsical star. Best part: you won’t lose any of your items.

Hidden Achievement
Arm Bar Arm Bar
Hidden achievement descriptions are missing by default. Why is it missing?

In the Labyrinth, in the hospital room where you find Curly is a chest with the Arms barrier: an item that decreases the amount of exp. points you lose when hit. To get it, you have to go through a small hole near the top just outside of the hospital. There are three ways of doing this:
1. Use your machine gun downward shot if you have it
2. Use your booster pack when you get it
3. Hop on the purple enemy near the hole (very hard but it works)

Here's Johnny! Here’s Johnny!
Obtained the Alien Medal!

To get the alien medal, you need to defeat Ironhead (the big fish in the Waterway) without getting hurt. I suggest that you save at the save room where you fix Curly. The easiest way to do this is to level up your blade to level 3 so that you can use it to take out all of the small fish, and to have your super missiles for Ironhead. Then just keep firing at Ironhead when he comes. If get hit, just restart and you’ll be at the savepoint.

Hidden Achievement
Count to 290 Count to 290
Hidden achievement descriptions are missing by default. Why is it missing?

This can only be obtained if you decided to take the “save Curly” route (all the way up until you save/lose Curly in the Waterway). When you arrive back in Mimiga Village, head to the Egg Corridor then head all the way to the right to get to the Outerwall. Then just go up a bit until you see a hole in the far left of one of the walls. Enter it, then open the chest to get the counter.

Hidden Achievement
Turbocharged! Turbocharged!
Hidden achievement descriptions are missing by default. Why is it missing?

If you decided to trade your polar star for the machine gun (see above), you’ll be able to get a free upgrade for it once you get in the Labyrinth. Just go through the Labyrinth as normal until you reach the shop (it’s to the left of the clinic where you find Curly). Talk to the bug at the counter (named Chaba), and he’ll give you an upgrade for your machine gun so that it recharges faster (you’ll also get the achievement).

Hidden Achievement
Little Man Little Man
Hidden achievement descriptions are missing by default. Why is it missing?

When you first get to the Outerwall, jump down and use your booster pack to go underneath the island. Head to the left and enter the door. Talk with the lady and she’ll say that her husband is missing (must talk to her first). Now head to the graveyard in Mimiga Village and you’ll see a tiny dot near the bottom of the area, which is her husband. Observe it (press down) so you can take him with you (which will grant you the achievement).

What A Fun Guy! What A Fun Guy!
Obtained Ma Pignon!

Can only be obtained if you decided to take the save Curly path. After you lose Curly at the Waterway, head to the Plantation, and head to the bottom right area. You’ll find Curly in a bed, all safe and sound… until you find out that she lost her memory. Talk to the guy next to her and he’ll say that you need a special mushroom to restore her memory.

Now head to the graveyard in Mimiga Village and go to the top right area. Use your booster pack to get to the door above. When you’re in, talk to the mushroom, and he’ll ask you some questions. Answer in order: Yes, yes, no, yes, yes, no. When you’re done talking to him, he’ll give you a mushroom medal. Observe it by opening it in the menu, and you’ll find that it’s worthless. Talk to him again, and you’ll have to fight him. Just shoot him with any gun (spur is the best) and be careful of the falling rocks and the clones of him that he’ll send. Once you beat him, you’ll obtain him as a pick up item.

Hidden Achievement
I've Got Your Back I’ve Got Your Back
Hidden achievement descriptions are missing by default. Why is it missing?

Once you get the Ma Pignon (see above), head back to where Curly is in the Plantation (bottom right area). Talk to her and give her the mushroom. When she gets her memory back, she’ll explain everything that happened prior to the start of the game. When she’s done talking, talk to her again and she’ll give you the iron bond, which will get you the achievement and ensure you that you can get the best possible ending.

Wanna Fight? Wanna Fight?
Defeated Balrog!

Near the start of the game when Toroko gets taken, you’ll have an option to fight Balrog. Choose yes, and fight him. He’s rather easy, though be careful of his jump attacks. Aside from that, just keep your distance and keep shooting him.

Rabid Mimiga Rabid Mimiga
Defeated Igor!

You’ll find Igor at the end of the Egg Corridor. Just keep shooting at him with either the polar star or missiles, and keep your distance.

What Are YOU?!? What Are YOU?!?
Defeated Balrog, again…

You’ll fight Balrog again when you get to the Bushlands and turn on the robot. He’s a bit more difficult than before, mainly because he flies above you and can land you you. I suggest leveling up the fireball and constantly fire it at him when he lands or when he’s in the air (aim up). Or just shoot him with the polar star.

Huge Toad Huge Toad
Defeated Balfrog!

You’ll fight Balfrog at the end of the Bushlands while getting pieces for the bomb. I suggest you level up your missiles before you fight him. When he’s coming to you, use the fans to fly over him and when he opens his mouth, fire rockets at him. Take care of the small frogs with the fireball.

Mimiga Bodyguard Mimiga Bodyguard
Defeated Curly…

You’ll find Curly when you arrive at the small house in the Sandzone. She’ll think your a mimiga killer and attack you (along with some mimigas). Use the fireball to take out the mimigas, and hit Curly with either the polar star or the fireball (she blocks all missiles). Remember to jump out of the way when she’s about to fire her machine gun.

Machine Monster Machine Monster
Defeated Omega!

Omega is located at the far right of the sand zone. To fight him, you’ll have to shoot him while he’s unleashing enemies. The fireball is the best choice since he spends most of his time in the ground. Once he’s done shooting, take out the enemies until he starts unleashing more. Also be careful of his jumps.

Make sure you have a dog with you before fighting Omega to get another achievement (see below).

Hidden Achievement
Ate A Red Flower Ate A Red Flower
Hidden achievement descriptions are missing by default. Why is it missing?

Once you gather all of the dogs in the Sandzone, you’ll be forced to fight rabid Toroko in the warehouse. She’s rather easy though: just keep firing at her and dodge her block throws (I suggest using the fireball to make this battle go faster).

Ghost in the Clinic Ghost in the Clinic
Defeated Puu Black!

When you get to the Labyrinth, you’ll have to head to an abandoned hospital to fight Puu Black. He’ll attack you with flying objects and will fly up and back down on you. Use King’s blade to take him out quickly (if it’s level one and you’re quick enough, you can defeat him in seconds). Be careful because you can still get hurt by him when he’s defeated.

Armored Feline Armored Feline
Defeated Monster X!

After you give Curly the cure-all in the Labyrinth, head to the right and you’ll have to fight a giant machine called Monster X. Take care of all of the cricket-like enemies first, and keep hopping over the monster when it’s coming for you. When the center of it opens, fire at it with either King’s blade or the missiles. Also be careful of the little green missiles that will circle around.

Rock Bustin' Rock Bustin’
Defeated Balrog, yet again…

In the Labyrinth, hop over the hole where Professor Booster falls down and enter the room. You’ll talk with Curly and have to fight Balrog for the third (and final) time. Even for the third time, he’s still really easy. He’ll just walk towards you everynow-and-then and fire a few missiles. Just hop over them and fire at him with any gun and you should beat him in no time.

Heart of the Island Heart of the Island
Defeated the Core!

If you jumped over the hole where Booster fell, go into the door and proceed normally. You’ll eventually enter a chamber with a giant seed-like machine (I highly suggest you grab the tow rope to the bottom right so you can save Curly afterwards). When you talk to Curly, the fight will begin. Shoot at it’s eye when it opens (I suggest using the super missiles) and shoot at the other enemies when it’s closed (keep in mind that you can hop on the other parts of the boss). Also make sure that you’re as high as you can be, because the area will flood everynow and then (and it usually takes a while for the water to come back down).

Big Fish Big Fish
Defeated Ironhead!

At the end of the Waterway (after you beat the Core), you’ll have to fight a robot shark called Ironhead. I suggest using King’s blade to take out the small fish that can hurt you, and when Ironhead comes toward you, use either missiles or the blade (or your default gun).

Defeating Ironhead without getting hurt will also earn you the “Here’s Johnny!” achievement.

Hidden Achievement
Only If You're Greedy... Only If You’re Greedy…
Hidden achievement descriptions are missing by default. Why is it missing?

When you get to the Egg Corridor? (the blown up version after you return to Mimiga Village), head to the right until you reach the destroyed egg observation room (the room where you originally got the missile launcher). Open up the chest in the middle and you’ll get an upgrade for your missile launcher. When you open it, you’ll have to fight two dragons. Firing at which ever one has there mouth open with a strong weapon such as the spur will prevent them from attacking you. If you can’t hit them in time, use your booster to dodge their attacks, and you should defeat them very easily.

Heavy Medal Heavy Medal
Defeated the Red Ogre!

If you obtained the iron bond by taking the save Curly path (see the I’ve Got Your Backachievement), and traded back your mimiga mask for the booster 2.0, you’ll enter a different version of the final cave. The cave consists of having to use your booster in tricky ways (to avoid hitting spikes) while getting past a few enemies. Near the end of the cave, you’ll have to fight the red ogre. Just use your super missile or spur and you can beat him in 10 seconds. Be careful of his jump attacks though.

Miserable Miserable
Defeated Misery!

After you get through the final cave and head to the right, you’ll now have to confront everybody’s favorite Cave Story witch, Misery. She’ll teleport across the area and will summon 2-4 dark balls that will orbit her. Aim at the right time with your spur or nemesis/sword to see the best results (save your missiles for later). She’ll also summon bats which can easily be destroyed, and blocks that can be appear above you (in that case, use your booster to quickly dodge it). When she summons three black balls that come towards you, use your booster to quickly go below them, so they’ll fire lightning bolts and you won’t be hit (otherwise they’ll keep following you).

House Call House Call
Defeated the Doctor!

After Misery, you’ll now have to fight the Doctor. He’ll fire red orbiting beams that can easily be dodged by boosting upwards, and he’ll also go in mid-air and release a burst of red beams (in that case, get as far away from him as possible). Aside from that, just shoot him with whatever, although be aware of his red crystal that orbits around him, which will block all attacks that hit it.

Muscle, MD. Muscle, MD.
Defeated the Muscle Doctor!

After you beat the Doctor’s first form, he won’t be able to control the full power of the red crystal and will transform into the Muscle Doctor. He’ll charge at you, so be ready to use your booster. He’ll also unleash a crap ton of bats at one time, which is why it’s helpful to have the spur with you. Fire at him just like with the normal Doctor, and by the time you know it, the Doctor will be dead forever!

Evil to the Core Evil to the Core
Defeated the Undead Core!

…Or is he? Head up after you beat the Muscle Doctor, and you’ll now have to fight the Undead Core. Fighting him is pretty much the same as the normal Core fight, although there’s no annoying water, and now Sue and Misery will attack you. When dealing with Sue and Misery, Just shoot at them with the spur. Misery will release a whole bunch of enemies every once in a while, which can also be defeated with one hit with the spur, and is helpful for gaining health. Aside from that, just fire missiles at the Core as usual (though be careful of his giant attacks that he’ll unleash when his mouth is open).

Hidden Achievement
Cave Story Clone Cave Story Clone
Beat the Wind Fortress Level

Wind Fortress is a secret level where you must use your booster on the bottom of the island to get to an area where you fight Curly clones. You’ll get the Cave Story Clone achievement just by beating it, but the others are only obtained by beating it within a certain amount of time.

Hidden Achievement
Swollen Mech Swollen Mech
Hidden achievement descriptions are missing by default. Why is it missing?

In the Blood Stained Sanctuary (the final area you go to by saving Curly), you’ll have to fight a giant machine called the Heavy Press. Use either your super missiles or your spur to take it out (it’s worth noting that Curly will also help attack it with her nemesis). Make sure to take care of the angels that’ll attack you, and when you defeat the boss, move out of the way or it’ll fall and kill you.

Hidden Achievement
Hate Made Flesh Hate Made Flesh
Hidden achievement descriptions are missing by default. Why is it missing?

After you beat the Heavy Press, you’ll reach the real final boss of Cave Story: Ballos. He has 4 forms.

For his first form, he’ll charge at you and will occasionally fly into the air to fire lightning bolts at you. Dodge them with your booster, and just fire at him normally.

In his second form, he’ll turn into a giant head that will hop around. Use your booster to go high and fire at his eyes to do damage.

His third form is the same as the second, except there will be eyes protecting Ballos, and he’ll move around on the walls and ceiling. Fire at his eyes and they’ll eventually be destroyed.

Now for his final form, use the platforms to get to his eyes, and just fire all of your missiles at him.

Hidden Achievement
Coward Coward
Bad Ending

After you escape the Labyrinth (whether it be by falling where Booster fell or by following Curly), you’ll be back in Mimiga Village. Head to the Egg Corridor via the teleporter, and head all the way to the right where you fought the rabid mimiga at the start of the game. When you enter the door and observe the computer, Sakamoto will come out and say that he plans on leaving the island. When he asks if you want to leave with him, choose yes. He’ll be waiting outside with his dragon and he’ll leave with you when you talk with him (I suggest that you save via the save button in the room next to the room you find Sakamoto so that when you quit, you’ll be right next to him). When you talk with him, you’ll fly away with him, get the achievement, and get a message saying that the Doctor eventually took over everything and that you lived your life hiding.

Hidden Achievement
Shtuff Happens Shtuff Happens
Complete Normal mode.

Get the normal or best ending while playing on normal mode.

Hidden Achievement
Curse Broken Curse Broken
Hidden achievement descriptions are missing by default. Why is it missing?

NOTICE: THIS ACHIEVEMENT IS BUGGED AND MAY NOT UNLOCK FOR MOST PEOPLE

Get the best ending by beating Ballos by doing the “save Curly” quest.

Hidden Achievement
Mimiga Hero Mimiga Hero
Hidden achievement descriptions are missing by default. Why is it missing?

Play the game normally until you get to the Plantation. After finding Sue’s mom, you’ll have to wear a mimiga mask so you can get parts for a machine. Once you do, you’ll have to go into the room where Sue’s mom was and take a nap. When you wake up, go outside, but do not talk to Sue’s mom because she will take away the mimiga mask. Instead, hop onto the rocket-powered lift while still wearing the mask (note that because you did not talk to Sue’s mom, you will not have your booster anymore, which means that you can’t get the best ending if you were planning to). Once you reach the top, just beat the game as normal and you’ll get the achievement (as well as a few altered ending screenshots).

The “mimiga” ending is technically viewed as the normal ending, so you can still obtain the “so easy” achievement (easy mode) but not the “shtuff happens” one (normal mode).

Hidden Achievement
Untouchable Untouchable
Hidden achievement descriptions are missing by default. Why is it missing?

To get this achievement, you need to get the normal ending without getting any health upgrades. Remember that to get the normal ending, you don’t need to do any of the save Curly sections (though if you’re trying to get the Unstoppable achievement, you’ll have to). I strongly suggest doing this on easy mode (or you could do it on hard and not get the life capsule that the dog gives you).

Hidden Achievement
Unstoppable Unstoppable
Hidden achievement descriptions are missing by default. Why is it missing?

Same thing as the Untouchable achievement, except that you need to get the best ending by beating Ballos. Again, I suggest doing easy mode for this achievement, since bosses will be weaker and and can take a bit more damage than usual. One thing that you should keep in mind is that during the Sanctuary level, there is no time limit, which means that you can take as long as you want.

So easy, so so easy! So easy, so so easy!
Completed Easy Mode

Get the normal or best ending (bad ending won’t count) while playing on easy mode. The only real main difference from easy and normal mode is that damage taken is halved.

I Like It Hard! I Like It Hard!
Completed Hard Mode

Get the normal or best ending while playing on hard mode. It’s worth noting that to get the normal ending, you don’t need to do any of “save Curly” sections (fighting the core, ballos, etc.). Main differences between normal and hard mode:

  • No life capsules (excluding the one that the dog gives you at the plantation, which means that you only have 3 HP for the majority of the game).
  • Missile launcher can not be obtained
Hidden Achievement
To Hell and Back To Hell and Back
Hidden achievement descriptions are missing by default. Why is it missing?

The Blood Stained Sanctuary game mode is the “hell” level that you play while trying to get the best ending (where you fight Ballos), except you can choose your weapons. Beating it will get you the To Hell and Back achievement, while beating it within a certain amount of time will grant you the rank achievements

Hidden Achievement
Sanctuary S Rank Sanctuary S Rank
Hidden achievement descriptions are missing by default. Why is it missing?

Check out this amazing guide created by steam user MasterLuigi452 for the best tips on how to beat it within 3 minutes. http://steamcommunity.com/sharedfiles/filedetails/?id=154331813

Hidden Achievement
Sanctuary A Rank Sanctuary A Rank
Hidden achievement descriptions are missing by default. Why is it missing?
Hidden Achievement
Sanctuary B Rank Sanctuary B Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Sancturay S-Rank” for more information.

Hidden Achievement
Sanctuary C Rank Sanctuary C Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Sancturay S-Rank” for more information.

Hidden Achievement
Who's the Boss? Who’s the Boss?
Hidden achievement descriptions are missing by default. Why is it missing?

Boss Attack is exactly what you think it is. You have to fight all of the bosses in the game in order, and you’ll be able to grab weapons and upgrades along the way. You’ll get the Who’s the Boss?achievement just by beating it

Hidden Achievement
Boss Attack S Rank Boss Attack S Rank
Hidden achievement descriptions are missing by default. Why is it missing?

Just follow the tips for the previous boss battles, although make sure you’re more accurate on everything. Also remember that there are a few life capsules that are blocked by a few pillars (you can get them easily, but they may be confused with exp containers).

Hidden Achievement
Boss Attack A Rank Boss Attack A Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Boss Attack S Rank” for more information.

Hidden Achievement
Boss Attack B Rank Boss Attack B Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Boss Attack S Rank” for more information.

Hidden Achievement
Boss Attack C Rank Boss Attack C Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Boss Attack S Rank” for more information.

Hidden Achievement
Wind Fortress S Rank Wind Fortress S Rank
Hidden achievement descriptions are missing by default. Why is it missing?

The best way to do this is to just completely ignore the enemies on the first part where you have to boost across the screen (though I would still use your spur to take out enemies in front of you). When you get to the inner area, do the same, though also use your spur to take out the monsters and the robot Curlys. When you get to the lab area, use your booster to fly over the slow moving Curlys, and head straight to the next room.

Now select your blade (best if it’s level 1) and talk to Curly. Now you’ll have to fight the G-Clone machine. Do not try and kill the Curlys and instead use your booster to fly up a bit and use your blade to keep hitting the computer screen when it’s blue. When it’s not blue, use your booster to dodge the Curlys. Follow this strategy and you’ll beat it in about 20 seconds (getting S-rank takes lots of practice).

*Actual achievement says that it needs to be within 4:00, but it’ll only unlock if done within 2 minutes. This is because it used to be within 4 minutes, but it was changed due to it being a bit too easy.

Hidden Achievement
Wind Fortress A Rank Wind Fortress A Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Wind Fortress S-Rank” for more information.

Hidden Achievement
Wind Fortress B Rank Wind Fortress B Rank
Hidden achievement descriptions are missing by default. Why is it missing?

See “Wind Fortress S-Rank” for more information.

Wind Fortress C Rank Wind Fortress C Rank
Completed Wind Fortress in Less Than 7:00

See “Wind Fortress S-Rank” for more information.

Hidden Achievement
Happy Birthday Pixel! Happy Birthday Pixel!
Hidden achievement descriptions are missing by default. Why is it missing?

Play Cave Story+ on Pixel’s birthday: April 29th (4/29/XX)

Fish Preserve Fish Preserve
Spared Eggfish

In the reservoir in Mimiga Village (where you found the silver locket at the start of the game), there is an orange fish. To get this achievement, you need to beat the game without killing it.

Hidden Achievement
Doggy Style Doggy Style
Hidden achievement descriptions are missing by default. Why is it missing?

Before fighting Omega (see above), go back to the house where you fought Curly and talk to one of the mimiga. They’ll say that Jenka is missing her dogs, and that you can carry the one in the back room. Go into the room and take the dog by pressing down. Now just beat Omega while carrying the dog and you’ll get the achievement.

Hidden Achievement
Return the Favor Return the Favor
Hidden achievement descriptions are missing by default. Why is it missing?

If you got the Iron Bond, go and beat the Undead Core, then go into the Cabin and fall down the hole to enter Hell. At the end of the first screen you’ll find Curly knocked out. Use your tow rope on her to get the achievement.

Weapons of Mass Destruction Weapons of Mass Destruction
Found and collected all Missile upgrades

After you get the missile launcher, you can start finding upgrades for it that increases the amount of missiles it can hold. Here are all of the locations:
1.) Bushlands: Head to the right of the save room door in the main area, and hop onto the platforms to the right to find the upgrade in a chest.
2.) Bushlands: Get up to the door pictured in the first screenshot via one of the fans, and you’ll find a chest with an upgrade (when you open it you’ll have to fight a rabid mimiga).
3.) Egg Corridor?: Under where egg #12 used to be.
4.) Egg Corridor?: Where the egg observation room used to be (when you open the chest you’ll have to fight the twin dragons).

 

Home, Sweet Home Home, Sweet Home
Returned Mister Little back home

When you get the little man (see above), take him back to his home at the Outer Wall and you’ll instantly get this achievement.

I'm Juggernaut... I’m Juggernaut…
Found and collected all Life Capsules

Life capsules are items found in the game that raise your health. There are 11 life capsules, and they can not be found on hard difficulty.

For all of the life capsule locations, check out my life capsule guide. 

http://steamcommunity.com/sharedfiles/filedetails/?id=203653302

Hidden Achievement
Toroko Wins! Toroko Wins!
Hidden achievement descriptions are missing by default. Why is it missing?

Before you fight Balrog, Toroko will try and attack you. Let her kill you and you’ll get the achievement (though remember to save before doing this).

Kings of Power Kings of Power
Accumulated XX,XXX of damage

You’ll easily get this by the time you finish the game. Just keep attacking every enemy you see and you’ll get this in no time (I got this while in the Labyrinth).

Merry Holiday Happy Euphemism Merry Holiday Happy Euphemism
For the rest of us!

(For some reason this achievement doesn’t have a picture)

Play Cave Story+ around the Christmas holidays. Will unlock if played on either Christmas Eve (December 24th) or Christmas Day (December 25th).