Here is the full list of all 12 SpongeBob SquarePants Underpants Slam! achievements worth 200 gamerscore.
Complete a Quest Mode game
Complete all Time Trial levels
Win a multiplayer game
Defeat 100 Jellyfish!
Collect 1000 underpants!
Break out of a Stun!
No pants in a multiplayer game!
Be ‘it’ for 50 seconds!
Use Super Moves 25 times!
Beat Quest mode with all 5 characters
Fall out of the level 50 times
Collect all the Gold Medals