Castle Crashers is a side-scrolling beat-em-up that incorporates a small number of role-playing video game elements. After selecting a character, the player then selects a starting stage through an overworld map. After completing a stage, the player has the choice to revisit it or to move to another stage. The map also displays shops where the player character can buy items and weapons using coins gained from defeated foes and chests. Arena stages can be unlocked where the player character can take on challenges to unlock additional characters.