IIRC V_R you played the demo and said it was a bit rubbish, which has put me off it ever since.
However, I just read the Review at Gamespot and they give it 8.7/10 and explain about the demo. It was pants, apparently, compared to the finished game.
Ability to save anywhere as well, that's always welcome (unlike within Crysis 2).
Oddly enough I picked up the original Gold Edition for £1 in a charity shop a few weeks back and had been playing it on my Win 98 machine until the PSU/motherboard went belly up. It reminded me how difficult it was when I first played it, never did finish it.
Did i? Lol, i dont remember. Its entirely possible!
Though its good to know the demo was not all that compared to the finished game. I actually got it before, in the Xmas sales most probably, still not played it though, should do really....