Braid

Braid is an incredible clash of arty sentiment, old-school platforming and mind-bending temporal logic puzzles. It starts off lulling you into a false sense of primitive-gaming security, negotiating ledges, bridges and gaps, before throwing some simple time-sensitive puzzles at you.

But rewinding time isn't the whole pudding. Here are some other elements that make this game so unique:

* The narrative, and the method of delivery. Piecemeal snippets of seemingly arbitrary text are presented to you at the beginning of each "world" (of which there are 6), through green books nestles on pedestals; the last level and epliogue are a huge reveal and twist rolled into one, with a very surprising message hidden just deep enough to be out-of-reach to the casual player. (The story is about the creation of the atomic bomb, essentially.)

* Green items are not affected by time. Green keys once used cannot be used again even if you rewind time to before you used it. Green enemies will soldier on regardless of your mashing of the X button. Green platforms and switches will remain in their current state.

* Purple items can be manipulated by a temporal echo of yourself. You can do something, rewind, and your shadowy alter-ego will perform the action again, allowing for tag-team interaction with the environment. Personally, these levels are some of the most innovative, taxing gameplay elements introduced in a very, very long time. Clever.

* The time-ring, which is a small golden ring dropped using the Y button, incorporating a time bubble around it. At the centre of the ring time stops dead; as you approach it form the outside, time slows down the nearer you are to it. This provides many memorable gameplay conundrums such as slowing down the firing rate of a canon, slowing down a platform's speed or a ladder's rate of decent, or even altering the rate of Mario-inspired potted plant traps to let an enemy through.

Braid took three years to make and $180,000 of creator Jonathan Blow's hard-erned cash to conceive. You owe it to yourself to buy this game. Now. This is the first time i've bought a game from XBLA and it is worth every penny.