Here is the full list of all 30 BattleBlock Theater achievements.
Make a trade with someone.
Complete 10 user-created levels in a single Featured Story playlist.
Collect all the prisoners of one head shape.
Get an A++ in 10 levels.
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.
Collect 10 Golden Hats.
Get 100 kills.
Play with the Behemoth or someone with this achievement in an online game.
Collect all the weapons in the Gift Shop by unlocking or trading.
Kill your teammate 50 times.
Find a secret level.
Free 50 prisoners in the Gift Shop.
Complete the first four finales in any mode.
Die enough times and we give you a prize.
Get eaten alive.
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.
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.
Complete an encore level in Story Mode.
Use each weapon successfully.
Download and host a game of user-created levels.