Update 5/3/2011: The Deal on Xbox 360 is over, but the PC version is still at $29.99; also, the PS3 version is now available and it’s on sale for $34.99 [that’s 42% off the list price of $59.99]. I’m not sure how long these will be discounted, so grab it now if you want it.

The video game deal of the day over at Amazon today is Portal 2 for Xbox 360 and PC.

– Xbox 360: $34.99 [42% off the list price of $59.99]
– PC: $29.99 [40% off the list price of $49.99]

Note, this deal is only for today, Sunday, May 1, 2011, til midnight PST while supplies last.

From the Xbox 360 product page:

* The single-player portion of Portal 2 introduces dynamic characters, fresh puzzle elements, and a larger set of devious test chambers. Players explore areas of the Aperture Science Labs and reunite with GLaDOS, the murderous computer companion.
* The two-player mode features a separate campaign with unique story, test chambers, and two new player characters. This mode forces players to reconsider everything they thought they knew about portals.
* Advanced use of physics allow for the creation of a whole new range of interesting challenges, producing a much larger but not harder game.
* A massive sequel to the title named 2007’s Game of the Year by over 30 publications worldwide.

Portal 2 is a unique first-person Action-Puzzle-Platforming game that tests player’s ability to think and act creatively as they use the game’s ingenious wormhole creating portal gun to produce their own paths through otherwise sealed surfaces and across the open spaces of the game. Sequel to the original Portal game — the surprise add-on hit included in Valve Corporation’s 2007 release The Orange Box — Portal 2 continues the storyline from the first game, featuring both new and returning characters, and poses a range of new challenges making for a much deeper game. Additional features include a new two player co-op mode and an original soundtrack.