Here is the full list of all 24 Super Turbo Demon Busters! achievements.
Have 10 guns in your arsenal
Earn 5000 credits
Complete your first quest
Kill 25 monsters
Complete your first raid
Kill your first monster
Kill three enemies with a shotgun round
Level up a mercenary once
Search 150 corpses
Break 50 crates
Kill 1000 enemies
Kill 250 monsters with a machine gun
Kill 2500 monsters
Kill 100 ghosts
Kill 5000 monsters
Kill 250 zombies
Complete 50 raids
Kill an enemy while your health is at 1%
Kill 10,000 enemies
Level up a mercenary 20 times
Complete 100 quests
Earn 50,000 credits
Unlock all mercenaries
Kill 20,000 monsters