My first over-hyped, over-ambitious 50-map megaproject that got nowhere. The basic idea behind it was "batshit insane gameplay," which even in its neophyte abandonedness managed to (somewhat painfully) nail on the head. Dual-wielding shotguns against hordes of projectile-dousing imp variants and cacodemons that spit ghostly fast demons? Sign me up.
Also, the cyberdemons shoot more cyberdemons.