I ordered Sonic Unleashed from Amazon...excellent and fast service, I got it quick, I played a few days...then got to almost clearing the game, but I came across a level in which everything would disappear, of course, I freaked out...then I figured it had to be a defective disc...I mean, I just bought this system 2 months ago so it couldn't be the console...here's a video to show how game breaking the glitch is:

YouTube - ‪MIND-BLOWING GLITCH: Adabat day stage Act 1‬‏

Of course this doesn't happen on others people's discs...so mine just had to be defective...the disc was still as clear as new, but I sent it back for replacement...I just want to know if somebody else has purchased a defective game on 360, or if the chances are just so slim that it might mean I was just really unlucky...