Braid is played by solving physical puzzles in a standard platform game environment similar to that of Super Mario Bros. with jumping and stomping on enemies to defeat them, and the player may also need to collect keys to unlock doors or operate levers to trigger platforms. One of the fundamental game elements is the player's unlimited ability to reverse time and "rewind" one's actions, even after dying. The game is divided into seven worlds, along with an "overworld" in the form of the main character's house. The worlds are entered through doors in the house. Each world has its own time-based game mechanic.