The guy behind the game basically got threatened by Zenimax, so he stripped out the copyright assets, renamed the game, and threw the source to the wild in hopes that even if Zenimax gets their way that the game will continue to live on.
Yeah, I heard about that. It's a shame that a lot of effort that went into the game art will get wasted because of a C&D threat, but it's safer to have something non-infringing instead anyway. Once all Doom references are out of the game the copyright owners will have nothing on it.
