A Mass of Dead Achievement List

Challenger Challenger
Cleared All Normal Difficulties of Challenge Stages
Soldier Soldier
Cleared All Hard Difficulties of Challenge Stages
Master Master
Cleared All Hell Difficulties of Challenge Stages
Survivor Survivor
First saw the ending
Awesome Weapon Awesome Weapon
Get the first unique weapon
Awesome Equipment Awesome Equipment
Get The First Unique Equipment
Equipment Master Equipment Master
Full Upgraded All Equipments
Flamethrower Master Flamethrower Master
Full Upgraded All Flamethrowers
SMG Master SMG Master
Full Upgraded All SMGs
Shotgun Master Shotgun Master
Full Upgraded All Shotguns
Equipment Collector Equipment Collector
Got All Equipments
Flamethrower Collector Flamethrower Collector
Got All Flamethrowers
SMG Collector SMG Collector
Got All SMGs
Shotgun Collector Shotgun Collector
Got All Shotguns
Weapon Master Weapon Master
Full Upgraded All Weapons
Item Master Item Master
Full Upgrade All Items
Weapon Collector Weapon Collector
Got All Weapons
Item Collector Item Collector
Got All Item
Challengers Challengers
Cleared All Normal Difficulties of Challenge Stages in co-op mode
Soldiers Soldiers
Cleared All Hard Difficulties of Challenge Stages in co-op mode
Masters Masters
Cleared All Hell Difficulties of Challenge Stages in co-op mode
Assemble! Assemble!
Cleared one stage in co-op mode