Here is the full list of all 14 Abacus achievements.
Beat the game.
Complete World 1.
Complete World 2.
Complete World 3.
Complete World 4.
Collect all Stars in World 1.
Collect all Stars in World 2.
Collect all Stars in World 3.
Collect all Stars in World 4.
Collect all Stars in World 5.
Collect every Star in the game.
Win a Deathmatch with 4 or more players.
Beat the dev time for any level.
Beat all dev times.