Here is the full list of all 20 ARK BOX Unlimited achievements.
Fire 100 Missiles
Destroy 1000 Blocks
Finish a 100 x combo or higher
Destroy 100 incoming enemies
Survive 10 Bossfights
End a stage with 3 active balls
Install all permanent Ark Upgrades
Reach the max. Ark size in a Stage
Create a stage and share it!
Finish a arcade survival run
Complete all Stages in Free Play and Arcade
Finish all Free Play Stages
Create 10 complete Stages
Download and play 10 new stages
Fire 1000 Bullets with the Ark Blaster
Collect 100 Power Ups
Collect 10 red Zonk Items and loose all size upgrades
Finish a Stage on the highest difficulty level
Finish a Stage in a max speed Arcade Run
Finish a Arcade Bossstage on max speed and difficulty