One of the coolest looking games at E3 2009 in my opinion was Shadow Complex, an all-new 3D side-scrolling action shooter from the guys at Epic Games (including Cliffy B.), makers of Gears of War, and “Chair Entertainment Group”, the company that developed the award-winning Xbox Live Arcade title Undertow.
An Xbox Live Arcade title powered by Unreal Engine 3, Shadow Complex features the best of old school side-scroller design combined with modern, cutting-edge gameplay and incredible high-definition graphics. Players collect power-ups, discover new abilities and evolve their character into a force of destruction as they explore an original new story set in the world of Orson Scott Card’s best-selling novel, “Empire.” Shadow Complex marries the quality and depth of a full retail title with the accessibility players expect from Xbox LIVE Arcade.
The game is also heavily inspired by great side-scrollers like Super Metroid, Castlevania and the Metal Gear series. Personally I think it looks awesome and insanely fun. It’s about time someone make a really great 2D side-scrolling action game/shooter! 
Here is the trailer for Shadow Complex.
“Shadow Complex completely redefines the bar for Xbox LIVE Arcade. It’s a testament to why Xbox LIVE is the clear choice in downloadable excellence” said Ken Lobb, creative director of Microsoft Game Studios. “XBLA look out, here comes the next UE3-powered smash!”
“The partnership between Epic Games and Microsoft Game Studios has resulted in Gears of War becoming one of the most successful video game franchises of all time, and we’re thrilled to further strengthen that relationship with the introduction of our newest game property,” said Dr. Michael Capps, president of Epic Games. “Just as Gears of War did for Xbox 360 games, we hope Shadow Complex will show the true potential of the Unreal Engine and Xbox LIVE Arcade.”
Here is the game’s E3 2009 gameplay stage demo debut.
Last but not least, here’s an interview with Cliff Bleszinski and Don Mustard, creators of the game.