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