Do you enjoy 2D platformers like Super Meat Boy? If you said yes or "Yes, but Super Meat Boy was way too hard!" then Super Ninja Warrior Extreme is a game you should download, try and immediately buy. One, it's nowhere near as brutal as Super Meat Boy or similar games; two, the controls are very responsive and extremely comfortable—jumping, wall jumps, and general movement just feels rights; and three, it's practically free with its one dollar price tag.
I've only dabbled in the game, playing through the first ten levels, but the few levels I played were enjoyable and well-paced. The music can get repetitive, but it never bothered me too much and the pixel art was nice and simple. As with all indie games on the Xbox 360, there's a free trial version which lets you play the full game minus the password functionality used for saving one's progress. (You can see each level's password in the pause menu, but you won't be able to input them unless you buy the game.) I highly recommend you give the game a shot and hopefully you'll enjoy it too. Super Ninja Warrior Extreme is a damn fine game and worthy of attention.
Super Ninja Warrior Extreme (XBLIG | 80 MS points)