Here is the full list of all 32 Another Crab's Treasure achievements.
Try on every shell in the game.
Learn all adaptations.
Fully upgrade Kril's fork.
Shoot a crab with a gun.
Unlock all skills on the Path of The Predator.
Defeated the Consortium.
Defeated the Scuttling Sludge Steamroller.
Purchase some insurance.
Get your shell back.
Defeated Firth.
Defeated Praya Dubia.
Defeated Camtscha (For real.)
Unlock all skills on the Path of The Hermit.
Defeated Camtscha.
Find a certain hero's helmet.
Defeated Inkerton.
Defeated the Royal Shellsplitter.
Defeated Petroch.
Defeated Roland.
Unlock all skills on the Path of The True Crab.
Defeated Voltai.
Defeated Pagurus.
Defeated the Ceviche Sisters.
Defeated Topoda.
Defeated Heikea.
Defeated the Curdled Carbonara Connoisseur.
Defeated the Diseased Lichenthrope.
Start the treasure hunt.
Defeated Magista.
Defeated a miniboss.
Fall off a cliff.
Defeated Nephro.