Here is the full list of all 17 Armored Kitten achievements.
Upgrade health for 100%
Complete normal difficulty
Complete 9th act
Complete 8th act
Complete 7th act
Complete 6th act
Complete 5th act
Complete 4th act
Complete 3rd act
Complete 2nd act
Complete 1st act
Complete 1st mission
Upgrade accuracy for 100%
Upgrade speed for 100%
Upgrade critical shot for 100%
Upgrade money drop amount for 100%
Upgrade enemy drop for 100%