Here is the full list of all 35 Droid Assault achievements.
Achieved security level 7
Defeated Level 40 Boss
Destroyed 100 robots with the disruptor
Maximum Overdrive buff
Maximum Damage buff
Maximum Armour buff
Maximum Battery buff
Flame, laser, and disruptor resistant droid
Defeated Level 30 Boss
Achieved security level 6
Maximum Recharge buff
Got Red Alert twice on one level
Buffed a droid in every aspect
Defeated Level 20 Boss
Command a full squad of 8 droids
Achieved security level 5
Got Red Alert status
Achieved security level 4
Defeated Level 10 Boss
Achieved security level 3
Achieved security level 2
Achieved security level 1
Completed Arcade Missions
Achieved security level 8
Achieved security level 9
Captured the Ultimate Droid
8 droids in ascending security order
Captured 3 9-series robots in same squad
Maxed every buff on a droid
Everything-proof and maxed-buffs droid
Escaped with 0 hitpoints and no squad
Fried 100 robots
Crushed 25 robots in doors
Defeated a boss with only a Sec Level 1 droid remaining
Started a level with 8 droids, finished with only 1