Ok. Demos often take up to a quarter of the size of the full game. You need to have the game engine, physics, and whatnot all there. Example? Empire:Total War was a HUGE 20gigs. Demo? 5 gigs. Demo had 2 battles and a tutorial, thats it.
Left 4 dead takes 7.5gigs. Demo? 1.7 gigs. And it was 2/5 of one quarter of the campaigns without versus... so 1/20 of half the game. My point has been made.







