BattleBlock Theater is a game developed by The Behemoth, where the player must pass all the levels in order to save Hatty Hattington, the best friend to one and all. The Behemoth also developed the game's storyline and the main character. In BattleBlock Theater, the player's objective is to collect all the gems and pass the "Boss Level", which is a usual level but with a time limit. In addition, the player can collect the balls of yarn to buy new equipment from the cat guards.

The game is inspired by the Japanese manga BattleBlock and was released for the Nintendo Switch and the PlayStation 4 in Japan in 2017.