1) Crysis 2 appears to have a VERY high skill cap, which is ideal for hardcoe PC gamers. This isn't your little brother's Call of Duty.
-The player health and weapon damage in Crysis 2 are almost identical to Crysis 1. Why is this important? Crysis 1 was designed without consoles in mind to be the best possible hardcoe PC-gaming experience. High health means head-shots are essential, and that good players can take out a room full of n00bs-- as opposed to a consolized series like Call of Duty, where it becomes a game of who-can-see-who first.
-In addition to the basic gameplay provided by Crysis 1, which as I above mention was designed for PC only, Crysis 2 adds advanced movement. Sliding, jumping, Mirror's Edge Parkour stuff-- all of this is an additional challenge not present in most first person shooters. Advanced movement has always been a part of major PC exclusive titles-- it takes us back to the good old days of Quake and Unreal. Since we're all better at aiming, we need an extra challenge.
-Not content to merely give us advanced movement, Crytek also provided us with Energy management. That energy bar means that some n00b sprinting around bunnyhopping is going to show up to a fight, button mash QQ, and die. The skilled player will always be trying to keep their energy high for when they will need it. Nano vision and stealth provide an extra layer of complexity-- more buttons that we need to hit, more mistakes n00bs can make, and a higher skill cap.
-Little details like intense inaccuracy if you don't aim down the sights, fairly small head hitboxes despite headshots being essential-- it all adds up to make this a very challenging and very hardcoe title.
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There's more that I could say, but those are the main points. From a gameplay perspective, I think Crysis 2 is going to be the best competitive mutliplayer PC game in years. It looks to have an incredibly high skill cap and rewards mastery. If you don't like it so far, remember that we're all still learning.
There are definitely some flaws, in addition to these good things. Wrote up a "Pros and Cons of Crysis 2" if anyone is interested in hearing a bit more.
I go into a bit more detail about some of this, and discuss a lot of the stuff that could be improved, here:
http://www.reddit.com/r/gaming/comments/fymbk/the_pros_and_cons_of_crysis_2/