Here is the full list of all 12 Oddest Sea achievements.
Win the game
Die
Die five times
Win the game in less than x minutes
Have 10 lampreys attached to your ship at one time
Heal at a buoy for the first time
Visit every buoy on the Oddest Sea
Have 5 sharks chase you simultaneously
Win the game with only 1 light left
Play the game 5 times
Play the game 10 times
Restore 5 light in one playthrough