Downloaded and played it this morning. All I can say is... OMG.
This game ROCKS.
There is about 45 mins of play time in the demo, dependant on how much time you want to spend wandering around and admiring the scenery.
The this to mention here is its open-endedness. You are given an objective on a island, i.e. "Go here and do this..." and perhaps a couple of hints on how to get there, but other than that, the method is up to you
You have a funky suit of armour which allows you four temporary power-ups, super strength, armour, a cloaking option and also super speed. Each of which give you a short burst of those powers.
One this that wasn't made particularly clear to me however was that I could pick up the weapons and ammo from the fallen enemies using the F key. I was told that I could pick up objects with it, I guess i just never tried the weapons
The other thing that gets me: With my AMD Athlon X2 4200+ (dual core), 2GB RAM and GeForce 7800GTX I am able to play all of my current games on the highest settings.
For Crysis I have to have everything on LOW. With that spec. Any attempt to put it higher results in a crappy framerate... There is a handy "detect optimal settings" button, however, which sorted everything for me.
But, even with it on low, the game is still BEAUTIFUL. I chucked a grenade at an enemy entrenchment and in as well as sending guards flying it sent dust and dirt everywhere and a few seconds later some nearby trees fell over too!!!
I think this game is gonna rock
PS: forgot to mention that there is seamless switching between cut-scenes and in-game too!
PPS: O and the emotions the guys you are with show are cool too