I've been posting this topic all over Halo. Actually just 3 forums, but yeah. Go figure. Sorry for the download link, but apparently the map wasn't allowed on HaloMaps yet.
What does it have:
* A custom single player path in a BSP by Bungie.
* Working music, i.e. Halo 2.
* Working cutscenes
* Alot of glitches to work out.
Known Glitches:
* The door doesn't open with the device, so I just made it dissapear.
* The marines at the beginning chatting is a bit of a mess.
* Sometimes, the turret isn't seated by a grunt. If it isn't, you'll have to use devmode to kill the grunt next to it. NOTE: This only happened in a later beta.
* In the latter half of the stage, you will encounter flood. The flood must be destroyed properly in order to advance. Be sure to kill all the infection forms, too. If you don't get a navpoint after you've had all the flood, restart from checkpoint/level.
* The level ends when the dropship flies off. The Chief will just stand, so your level is done after that.
* There are other minor AI glitches, but most are unnoticable.
Pics



Download
HaloMaps: http://hce.halomaps.org/index.cfm?pg=3&fid=3076
Megaupload: http://www.megaupload.com/?d=XOV79200