Here is the full list of all 28 Captain Coffer 2D achievements.
Completed a stage with only one doubloon remaining.
Completed a stage with at least 45 seconds left.
Wielded the effects of the MAGIC KEY and CROWN OF RICHES power-ups at the same time.
Dropped a Classy Coco from a precarious platform to a fateful end.
Electric Enemy zapped away an incoming doubloon blast.
Banished 64 Classy Cocos.
Blasted 64 Gold Doors.
Blasted 64 Gold Crates.
Completed Stage 01.
Completed Stage 02.
Completed Stage 03.
Completed Stage 04.
Completed Stage 05.
Completed Stage 06.
Completed Stage 07.
Completed Stage 08.
Completed Stage 09.
Completed Stage 10.
Completed Stage 11.
Completed Stage 12.
Completed Stage 13.
Completed Stage 14.
Completed Stage 15.
Completed Stage 16.
Completed every stage in Captain Coffer 2D.
Completed a stage without getting stunned.
Unlocked all achievements in Captain Coffer 2D.
Blasted the ship's cannon on Stage 12.