The increased availability of indie games in the last few years has definitely brought with it a rise in critically acclaimed games that, if they were movies, would fall squarely into the "arthouse" category. We saw Braid in 2008, Limbo in 2010, and for our money, 2011 has Superbrothers: Sword & Sworcery EP. This adventure game is not incredibly difficult, and can be finished in mere days, but it will stick with you long after you've finished. The intentionally pixelated art style looks amazing, but still allows you to bring your own imagination to the table. The audio begs you to plug in your best headphones so you don't miss a note. The story is high concept, and the learning curve is consistently "right." It keeps you thinking about how to move forward, but provides the perfect level of guidance when a new gameplay or control element is introduced. There's a lot of shovelware in the mobile market, but this rises above it to become something truly special.
While not as high concept as our winner, Mage Gauntlet almost takes the opposite approach and distills all of the best familiar aspects of classic action RPGs into an incredibly fun, easy to play app. Also it easily captures the 2011 award for most hats.