Porting other games to the Doom engine (or actually to it's derivated sourceports) is something, people already do for a while now. Doing it as close as possible to the original game engine is a difficult task though. If you are as old as I am (34 years now), you might still remember the good old times when egoshooters had pixels as huge as thumbs and only 16 colors to help your imagination killing demons and skeletons - just as in Catacomb Abyss, the grandfather of Doom. The modder inferion seems to be my age, for what other reason should someone consider porting the game to GZDoom? He did a very good job, it's not perfekt yet but I had that good old feeling when playing the project, listening to the pc speaker sounds and blasting my way through the secret walls again - just as I did 28 years ago... hell I am old. Keep up the good work and please improve the little flaws before you continue with the next installment ;)