I've put around 6-8 hours (360 version) into the game's campaign and judging by the chapter list in the extras menu - I have around 4-5 chapters left depending on where I am upto (can't remember exactly).
The game is amazing - up among the best shooters ever.
Graphics are incredible. I played a good portion of the KZ3 SP and it's just no contest for me. Everything in C2 looks fantastic and I haven't noticed too many performance issues (cloaked sniping tends to get the game choking). That said, there are some strange oversights such as keypads/buttons for some things that look PS1 bad and ridiculously awful paper effect when activating printers/copiers.
I really like the story taking place almost entirely through your visor - it made the Onyx building scene one of the best moments in videogames for me, and it helps greatly in keeping me immersed. That said, the silent hero was not a good choice. It works in Halo because Master Chief is an elite, tailored-for-war, badass, cold steel, probably gave your mother the only orgasm she ever had, awesome silent type - because you know who he answers to (only chuck Norris), and what his purpose is. I feel none of that in crysis, I'm some bitch marine who doesn't do one thing before getting fucked up and getting lucky enough to be found and suited up. To top it off, who the fuck is Gould and why am I following his instructions? I'm just not sure that in a reasonably decent plot - that having a silent unproven hero was the best choice.
The MP is a blast - more of the same from the demo, which I loved. My K/D is currently sitting at 2.89 and I can feel the COD whore creeping out of me.
Oh and dat audio - great effects and music. Second to Reach for soundtracks this gen for me.
Well done Crytek, I'm happy they went this direction instead of C1 - will be there for that Kingdoms game day one.