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