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