The main part of Braid's gameplay is in worlds. Each of these worlds contains a number of levels that Tim must complete.
Each world is accessed through a door in Tim's House. For other doors to be unlocked, previous levels need to be completed. This doesn't mean that all Puzzle Pieces need to be collected and put together, only that Tim must finish the final level of the world, regardless of how it's done.
Each world has its own unique mechanic (with the exception of World 2 and 3) which affects time.
World 2 and 3 are different to the other Worlds, because they both introduce an aspect of the game which is then used in the rest of the game. All other Worlds have a unique mechanic which is available only in that World.
World 2. Time and ForgivenessEdit
- Main article: World 2
World 2 introduces the game, by providing the player with instructions as to the controls, and Tim's ability to reverse time. It also introduces simple obstacles, and in later levels puzzles that require Tim to manipulate time. World 2 is the simplest of all Worlds, as there is no unique mechanic in it.
World 3. Time and MysteryEdit
- Main article: World 3
World 3 introduces Glow, and glowing objects, which are not affected by time, and have their own timeline. It shows how Tim can use his time reversing together with glowing objects to solve otherwise impossible (or difficult) puzzles. Glowing objects appear in all other Worlds after World 3.
World 4. Time and PlaceEdit
- Main article: World 4
World 4 links the passage of time to the player character's location on the horizontal plane. As the player moves toward the right, time flows forward, while moving toward the left reverses the flow; standing still or moving vertically will pause time. The player's location must be carefully managed in relation to enemies and objects.
World 5. Time and DecisionEdit
- Main article: World 5
World 5 involves a "shadow" of the player character appearing after the player rewinds time and performing the actions that the real player character rewound; if the timeline expires, the shadow will complete any initiated falls and jumps but will otherwise stand still before disappearing. Things coloured in violet can interact both with the main character and its shadow at the same time. Puzzles in this section revolve around using this mechanic to carry out multiple actions at once.
World 6. HesitanceEdit
- Main article: World 6
World 6 provides the player with a magic ring which, when dropped, warps the flow of time around itself; the closer moving objects (including Tim) are to it, the slower time passes for them. The regular rewind control remains available.
- Main article: World 1
In this world, time flows in reverse. Rewinding time returns the flow of time to its normal state.