I recognize that music
That's a remix of doom 2 map 9. "The Pit". While the animation with all the barons facing the cyberdemon was map 8, "Tricks and Traps". You know, you're not supposed to shoot them, you're supposed to let the cyberdemon fight the barons. It's easy to get well under par even doing so.
Some of the animation was lacking at some points and so I give it a 9 only because if I didn't reserve 10 for the truly awesome that would detract from the meaning of me giving something a 10. Also it's not really very unique to animate that sort of random fan generated might-have-been scene in some possible Doom scenario. Especially with the simplistic look of the artists' rendering of the imps being so emphasized. But it's interesting, this was 3 months and a day before the doom movie hit the theaters and you've got doom 3 stuff in it. I didn't think doom 3 was actually very popular by then but you really were on the ball there.
I have to say though, 2 things in particular I really, really liked. You may rate my comment down for being stuck on 2 such trivial things, but here they are. One is the scientists at the very beginning as they play out the background story of doom, making the teleporter and Deimos disappearing, while all hell breaks loose on Phobos. Particularly the scientists' hair. If you ask me, THAT'S how scientists should look in the future! Or at least the ultra-smart scientists who design teleporters that open gateways to hell and could no doubt outthink any scientist of today. It's just so futurey. Or maybe my mind is just polluted by 80s time travel movies like Millennium, but that is a stereotype scientists should strive toward if you ask me. The other thing that got my notice was what you did with the doom logo, where the texture background to the pyramid and sky was animated to move. I think that's the way the doom logo should look by golly. I thought that was just swell. I guess that's about it.
So almost a 10.