It's been an interesting year for the Xbox 360, and honestly, it's not really a stretch to say that most of the 360's best games were third-party releases that also appeared on other platforms. But there were still a few kick-ass gems on Microsoft's machine in 2009, so we're going to specifically call those out here with the year's best Xbox 360-only games.
Best Xbox 360-Only Game
Chair Entertainment's Shadow Complex stands alone in 2009 as the best game that was only made available on Microsoft's home console. It's a great action-adventure that straddles eras by recalling some of the best games that previous generations had to offer while modernizing the process in a way that makes the whole thing feel very much like an all-new experience.
As Jason Fleming, an everyman who just so happens to have a bit of weapons training under his belt, you'll infiltrate a shady fortification full of bad guys who are plotting to overthrow the United States, build a powersuit that gives you additional traversal abilities, and eventually shut the whole place down. The additional skills you get, like double jumps, speed running capabilities, better weapons, and even a shield that makes you practically invincible as long as you move slowly, make the game a joy from start to finish because you're always acquiring something new that makes you rethink the different ways to get around this side-scrolling world. Missiles open doors, foam lets you create platforms, and a grappling hook lets you hook onto and climb to places that felt completely impossible to get to only minutes before. With its satisfying combat and plenty of enemies to eliminate in a lot of different ways, just fighting your way from place to place is exciting as heck.
Then there's the meta-game to Shadow Complex. The way the game challenges you to collect every single item, or gives you a set of well-conceived leaderboards for things like headshots and melee attacks, or the way you can speed run your way through the entire game in a fraction of the total time if you know exactly what to do makes Shadow Complex a very replayable game that feels very different when you're attempting to achieve these alternate goals. On top of that, there's the Proving Grounds, a set of out-of-game challenges that give you some very tricky tasks to accomplish, as well.
It looks great, and it's a downloadable Xbox Live Arcade game that launched at $15. You can't find it anywhere else, and it's the best thing going on the Xbox 360 for 2009.
Runners-Up: Halo 3: ODST, Forza Motorsport 3