Here is the full list of all 18 Crab Dub achievements.
Pop 100 bubbles
Beat the game!
Unlock the final boss!
First zone completed!
Kill one Octopus
Jump 10 times on jellyfish
Second zone completed!
Chop 100 ice cubes!
Use 10 hearts
Destroy 10 apples
Destroy 10 missiles!
Start the game on the little duck!
Third zone completed!
Inflate 10 kittens
Jump 100 times on a space donkey!
Start the game in space!
Activate the magic pill!
Start game for the Crab!