Crysis 2

All I remember: you go to an island looking for researchers, turns out there are 'aliens' buried underground, you escape and something hints that Prophet is not a normal person. The end.

I played the demo on 360 and I'll give you my unbiased review: It's exactly like COD4:MW with the addition of sliding, camouflage, assassinations and armor. When I say exactly I mean exactly almost as if they ripped the engine out directly. It even comes the same type of class system (4 preset and a few create your own slots), same perks (3 tiers of perks), same weapons ( 1 main, one sub, attachments, etc.), same kill streaks (3 radar, 5 airstrike, 7 helicopter) . I have no opinion on that matter of whether or not this is a bad or good thing that they blatantly copied the call of duty series. I did not play crysis one but I suspect the gameplay is vastly different. Here's the stuff that's different from call of duty:

The Melee System: Is a punch that kills in one hit like a COD knife, if you punch someone from behind you go into a little assassination animation which takes time and can get you killed, but it gives you some extra points.

Energy System: Armor, Sprint, and Camouflage all share one energy bar. They can be kept on until your energy drains to 0. Armor and camouflage overwrite each other but you can sprint with either one of them on. The energy recovers pretty quickly when not using one of the 3.

Armor: Causes you to take less damage and deal more damage. It supposedly causes a melee to require two hits to kill you.
Impact on gameplay: I think it skews gameplay too much, you never know how many shots it's going to take to kill someone because you may not have your armor up (increasing your damage) or they might have theirs up (reducing the damage you do) thus making melee very effective and weapons unreliable.

Sprint : Works like a normal sprint except you can tap crouch ( I could be wrong on which button) and preform a power slide, you can even shoot while sliding, but it's very difficult to aim.

Camouflage: My personal favorite, The less you move the less visible you are. If you preform an action other then sprint or climb all your energy is drained and you get flashed. Sounds horrid but you just toggle it off before shooting, meleeing, throwing nade, ect.
Impact on gameplay: Promotes camping big time, very easy to camp and one shot melee people or groups of people as they pass by.

Killstreak System: The killstreak system is exactly like COD's except one minor detail, all your kills don't count, you have to pick up a "dog tag" by walking over it on the ground and pressing "A", which means you have to go to their dead body.
Impact on gameplay: Promotes the use of CQC and discourages the use of guns.

My take on the game: Visually stunning and fun, but ridiculous from a competitive stand point. I would go 20 kills and under 3 deaths every game just by camping with camo in high traffic areas, with a proximity alarm perk, and one hit meleeing people. The guns were so unreliable that out of the 20 kills 2 would be from guns maximum. Sniping was impossible players move too fast, very few highground locations on the map, players moving stealthed, and inability to collect dog tags from your cross map kills (no kill streaks for you). The whole system seems to gear towards meleeing way too much.

I recommend this game only if you enjoy the COD series starting from COD4:MW and above, if you like camping, enjoy not getting sniped from across the map, or if you like knifing people. Sounds sarcastic but its not, if you like all that then by all means have at it. If you don't steer very clear from this game.