Stumbled across this game recently, and it was by far one of the purchases I've ever gotten.
This game is like Star Fox on crack.. and puts said Star Fox to shame. I'm also extremely surprised by the sheer amount of depth to it from the different abilities and forms you have. For a simple rail shooter, this game is damned impressive. It also has some of the most impressive and exciting boss fights I've seen in a long time. On top of all that, the story is surprisingly interesting so far, and production values are jawdropping. It's amazing how something so seemingly simple and arcadey can produce similar feelings you might have while watching a full blown anime epic.
Overall, this game is fantastic so far. Anyone who even remotely likes rail shooters and has an Xbox or Xbox 360 should totally buy this game.