What I've read back then in several msg boards and youtube, was that alot of guys spend a lot of time developing and shaping the stages etc. and that they were used without permission of the ones who made them.. again, I have no clue what is true tbh.
But who cares, I mean sure it looks awesome..
But the gameplay sucks ass, it's unbalanced and the screaming audio will bore you after 30min's.