Here is the full list of all 29 Assault Android Cactus achievements.
Finish any level without taking damage
Unlock all items in the Codex
Play as 8 Androids
Rescue the Genki Star
Destroy seven enemies with a single Rail Gun shot
Destroy 15,000 homicidal robots
Destroy 3 enemies by driving another enemy through them with the Giga Drill
Defeat Superstructure Engineer Venom
Defeat Security Administrator Justice
Destroy every laser fence In Justice's first phase
Cause 3 mines to explode in succession without being shot
Destroy an enemy with Helo while it's caught by a Singularity
Defeat Hydroponics Controller Vespula
Activate an EX Option
Unlock any item that costs credits
Defeat Production Overlord Embryo
Earn an S+ rank on any level
Reach a chain of 100
Defeat one of Embryo's phases before he can relocate
Collect every Battery dropped in the Collider level
Reach a chain of 1000
Reach Layer 15 in Infinity Drive mode
Reach layer 25 in Infinity Drive mode
Complete Boss Rush mode
Lead the laser turret to defeat Medulla
Earn an S+ ranking on all campaign levels
Drop a cannonball down the hole in Filament
Unlock all items in the Art Gallery
Unlock all items in EX Options