I'm all but positive it wasn't an official game, as it didn't seem like one and I can't find any information about it anywhere else. But this is a game that I think my dad brought home from somewhere, or maybe got in the mail or something, on a CD-ROM. It ran on Windows 95/98 (though I guess it might have been 3.1 or DOS) and I remember it didn't work very well, like it had game-breaking bugs or crashed a lot or something. The most specific thing I remember is that the first level was called "Robotropolis Zone" and had the music from Flying Battery Zone. The name "Sonic 2000" sticks in my head, but I don't have a lot of confidence in that. All I can find with that title though is this NES bootleg which wouldn't have been it, and this page that mentions a fangame for DOS but doesn't contain any specific details. Again though, it could very easily have been called something else; that's just something I feel like it might have been called. I know Sonic Robo Blast has a level called "Robotopolis Zone", but that wasn't it. EDIT: Oh wow, I just realized I asked about this over a decade ago and got the answer, and completely forgot. And that's not even the first time that's happened to me here. What the hell is wrong with my memory?