I can see why id made this semi-official. There are a couple of lesser maps but the whole thing oozes quality and certain levels really brought a smile to my face. Doom Zero is a much better fan-made entry in the series than Final Doom and honestly I think I like it more than vanilla Doom 2. The only real issues are the focus on "platforming" and a few obnoxious switch puzzles, which are definitely gonna kill the replay value for me a bit. Still, this is a fantastic megawad/game in the end and absolutely worth any fan's time.