Here is the full list of all 30 BattleBlock Theater achievements.
Kill your teammate 50 times.
Make a trade with someone.
Play with the Behemoth or someone with this achievement in an online game.
Get a letter grade in every level (except Encores) in insane solo story mode.
Collect all the prisoners of one head shape.
Successfully use every melee attack move.
Be on the winning team in 100 arena matches.
Get 100 kills.
Be on the winning team in one arena match of every mode.
Download and host a game of user-created levels.
Complete 10 user-created levels in a single Featured Story playlist.
Complete all the Encores in any mode.
Get a letter grade in every level (except Encores) in Normal Solo Story Mode.
Get a letter grade in all eight finales in any mode.
Die enough times and we give you a prize.
Collect all the weapons in the Gift Shop by unlocking or trading.
Free 50 prisoners in the Gift Shop.
Complete the first four finales in any mode.
Get eaten alive.
Find a secret level.
Complete an encore level in Story Mode.
Get yourself a cool new weapon.
Free a fellow prisoner.
Get an A++ in 10 levels.
Complete the story's opening sequence in any mode.
Get a letter grade in every level (except Encores) in Normal Co-op Story Mode.
Get a letter grade in every level (except Encores) in insane co-op story mode.
Collect 10 Golden Hats.
Free all the prisoners in the Gift Shop by unlocking or trading.
Use each weapon successfully.