Looks pretty decent there's a quick look video here -
http://www.gamerss.co.uk/?p=192507
GAME INFORMER | Game of the Month; Game Informer Gold | 9/10 || Concept: Dropping the Tomb Raider moniker, Crystal Dynamics changes the equation with a new camera and co-op play neatly wrapped in a downloadable package; Graphics: Employing the Tomb Raider Underworld engine, the enviroments, lighting effects, and character renders are polished as their big-budget counterparts; Sound: Populated with both iconic and original music, the former grounds the game in familiarity while the latter plays up the new, action-centric direction. Some of the voice acting could use a once-over, though; Playability: Despite the arcade influences, Lara's moveset isn't reduced in the slightest. Co-op play allows for more diversity in puzzle solving, and the analog shooting lends itself nicely to the frenzied combat. Entertainment: Balancing the franchise - exploration, puzzles, and platforming - with the new combat-centric focus is both engaging and entertaining. Even when solving puzzles, downtime is rare; Replay Value: Moderate.
GAMES MASTER | 8.8/10 || Should you have asked us six months ago what could propel the nation's gaming sweetheart back into our affections, chances are that a £10, download-only arcade shooter wouldn't be our first guess. However, Lara lust strikes again - this has convincingly won us over. [...] A superb co-op game that hits all the right notes. The puzzles are brilliantly tricky, the shooting violently satisfying.
EUROGAMER | 9/10 || Guardian of Light would almost be worth a full price for the co-operative campaign alone. At 1200 Microsoft points - around £10, €15 or $15 - it's an instant buy. There are few download games that offer this kind of value for money, and few that are as clever or effortlessly exciting. Lara Croft and the Guardian of Light might be a move away from the Tomb Raider name, but it's a tremendous homage to its spirit.
JOYSTIQ | 4.5/5 || In terms of level design, pacing and gorgeous visuals, Lara Croft and the Guardian of Light topples last year's XBLA king, Shadow Complex. But while a lot of this content is perfectly suitable for a six-hour single-player session, I'd urge you to discover the game for the first time with a co-op partner. If that means you have to sit on it until online functionality is added on September 28th, then do it. In the meantime, buy the game, pick up the phone and try to get a friend on the couch for some Spider Bowling.
IGN | Editors' Choice | 8.5/10 || Lara Croft and the Guardian of Light is a great adventure, especially if you're playing co-op. Despite the silly story and dialogue, I had more fun with it than any Tomb Raider in recent memory. With a great new look, clever puzzles, and loads of fun stuff to collect, this is an extreme makeover for Lara of which you will surely approve.
1UP | A- || Though the game would still be fantastic with its co-op dungeon puzzles alone, Guardian of Light contains a surprising amount of substance; each of its many levels offer a series of achievements that add interesting weapons and items to your inventory. There's a definite focus on loot in Guardian of Light, and while it's nothing as substantial as what's found in games like Torchlight, the game offers a respectable amount of equippable goodies for both Lara and Totec to discover -- which also gives you a good reason to dip back into previously-played levels.