This is a video showing a big audio bug in the Xbox 360 version of Rez (called Rez HD). In the first level the enemy TX plays out of tune in the HD version (precisely one semitone wider that it should be). This bug hasn't been corrected as of March 2010 despite the update capabilities of the Xbox Live Market. :(
There's some other bugs, for instance in the French version of the last level's popups, some English words are left untranslated ("commencera a new...")
Nontheless, Rez is a great game. Buy it, play it !