I was prepared for horribleness thinking it's a RE4 mod with Doom stuff in it. This is pretty clever however. I might even try it. It's kind of a shame it's not a TC with Mercenaries style levels, scoring, co-op, etc though. All of that should be possible in the Doom engine if I'm not mistaken. Still, it also shows how much you can do with primitive engines with some clever design ideas, further proving it's mostly graphics that have improved over time, not so much the gameplay possibilities. RE4, ie, the modern third person shooter, could have apparently more or less been done 20 years ago if someone had actually thought of utilizing that style cleverly.