Here is the full list of all 30 Sayonara Umihara Kawase achievements.
Fail a Stage 50 times.
Acquire 10 backpacks.
Watch the Stage Tutorial of a Stage you've cleared.
Clear the second door in a Stage.
Clear Survival Challenge.
Play Survival Challenge.
Browse the Illustration Gallery.
Clear Sayonara UmiharaKawase +.
Clear Tadpole.
Acquire two backpacks at the same time.
Fail a Stage 20 times.
Check all Walkthrough Tips in the Gallery.
Browse the Sound Gallery.
Fail a Stage while holding a backpack.
Acquire a backpack.
Unlock all Stages.
Clear all doors.
Use all characters.
Acquire 30 backpacks.
Acquire 45 backpacks.
Clear Crab.
Clear Balloonfish.
Clear Tadpole 2.
Clear Crab 2.
Clear all routes on Survival Challenge.
View everything in the Illustration Gallery.
Play everything in the Sound Gallery.
Watch all Stage Tutorials.
Play your own Replay 10 times.
Catch a Tadpole.