Here is the full list of all 8 Build 'n Bump achievements.
Save 50 custom levels.
Save 10 custom levels.
Build a level with every block type.
Bump 5,000 robots total.
Bump 1,000 robots total.
Score 100 points in Practice mode (single-player).
Play every game mode at least once.
Play Battle mode with six people (local or online).