Here is the full list of all 67 Ultratron achievements.
Maximum droid power
Defeated two bosses
Laser pet levelled up to maximum
Defeated Letum
Full complement of smartbombs
Upgraded all pets to maximum parameters
Killed 100 enemies with grenades
Smartbombed 25 enemies with one blast
Defeated Lues
Upgraded laser pet to maximum
Smartbombed 10 enemies with one blast
Upgraded shooty pet to maximum
10 kills with a single grenade
Single drone shot down 100 enemy bullets
Single drone vanquished 250 enemies
Maximum drone upgrades
Defeated Bellum
Beat a level without firing a single shot
Got 100% on a dodge stage
Maximum dot slurp range
Survived assault level without taking damage
Held one or more pets for 5 levels without dropping
Consumed 10 consecutive fruits
Collected 10 fruits
Collected 1000 dots
Vanquished 1000 enemies
Defeated Ieiunitas
Got 100% on a challenge stage
Collected 500 dots
Vanquished 500 enemies
Maximum score multiplier
Player has fired 1000 shots in a game
Collected 250 dots
Collected 100 dots
Vanquished 100 enemies
Detonated 25 smartbombs in a single game
Vanquished 2500 enemies
Vanquished 5000 enemies
Vanquished 10000 enemies
Collected 25 fruits
Collected 50 fruits
20 kills with a single grenade
30 kills with a single grenade
Killed 500 enemies with grenades
Killed 1000 enemies with grenades
Maximum shields
Upgraded rocket pet to maximum
Shooty pet levelled up to maximum
Rocket pet levelled up to maximum
Grenade add-on upgrades maxed
Drone survived 10 levels
Drone survived 20 levels
Drone survived 30 levels
Awesome double three way bouncy gun
Double three way bouncy bezerk gun
Double three way bouncy max power rapid fire gun
Player has fired 10000 shots in a game
Player has fired 100000 shots in a game
Detonated 10 bombfruits
Smartbombed 50 enemies with one blast
EMP shocked 10 enemies in one blast
EMP shocked 25 enemies in one blast
EMP shocked 50 enemies in one blast
Maxed turbo power and recharge
Quantum-shifted through a boss
Held one or more pets for 10 levels without dropping
Held one or more pets for 20 levels without dropping