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