From Earth Achievement List

Student Linguist! Student Linguist!
Unlock 10 alien sentences.
Huuuugs Huuuugs
Hug 30 aliens.
Pew! Pew! Pew! Pew! Pew! Pew!
Build a laser gun.
Pacifist Pacifist
Finish the game without you or you followers hurting any living beings.
Peaceful Peaceful
Finish the game without attracting the alien government to attack you.
We come in peace We come in peace
Finish Chapter 1
New Friends New Friends
Finish Chapter 2
New Enemies New Enemies
Finish Chapter 3
Stay there Stay there
Take out 6 enemies without killing them.
Master of disguises Master of disguises
Find and wear all eight disguises.
I'd buy that for a dollah I’d buy that for a dollah
Buy 10 items from stores.
Save Anthony Save Anthony
Save Anthony before it’s too late (in Notorious run).
Notorious Notorious
Finish the game becoming notorious.
Expressive Expressive
Use gestures to explain English 3 times.
Master Linguist! Master Linguist!
Unlock 20 alien sentences
Kiss cam Kiss cam
Take a photo of an alien while they are kissing.
Brush your teeth! Brush your teeth!
Take care of your dental hygiene.
Just a fellow Entrulian here Just a fellow Entrulian here
Find a way to disguise yourself
So polite! So polite!
Unlock the 10 polite sentences.
Skeletons Skeletons
Play through all of Chapter 2 as a skeleton.
Too cool for school Too cool for school
Have the sunglasses in your inventory by the end of chapter 3.
Save Kra Save Kra
Save Kra from becoming Panasunyss (in Pacifist/Fighter run).