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