Here is the full list of all 16 Caterpillarnoid achievements.
Defeat the boss
Defeat the boss (hard/very hard)
Complete all levels with ships
-1 sec of poison duration
-0.9 sec of freezing duration
Don't give up!
200 fireballs
Gather some flowers
Destroy 50 enemy's projectiles or bombs
Destroy 150 enemy's projectiles or bombs
Defeat 50 enemies
Open 50 ammo boxes!
Collect 100 coins
Open 25 chests
Get 100 000 score
Break 1 000 bricks