For those of you who are getting stuck, or just plain frustrated with Doom 3 here are some cheats. Be sure to check out Futuremarks forums for the complete list of cheats.
Bring the console up with [~] and type the following codes in.
- aviDemo = Saves a demo of your playing to an AVI movie file
- benchmark = Game Benchmark
- doomhell = Skip all levels to last
- freeze = Freeze all on screen
- gfxinfo = Graphicscard infomation
- god = God mode
- noclip = No Clip
- notarget = Invisibility to most enemies
- com_drawfps 1 = Show FPS
- give all = Full load of weapons and ammo