The maps on Crysis 2 felt very tiny and linear and almost gave a claustrophobic feeling after playing Warhead. There were really tens of ways completing Warhead because the maps were huge and had boats, vehicles and lots of enemies on them while in C2 it felt like you were forced to complete the game always the same way, by moving through those narrow maps.
The graphics were overall better in Warhead(not going to all details here)
and you could really mess around with the koreans.
and the most important thing: the nanosuit.
Crysis 2 is supposed to have the improved version of Nanosuit. So why the hell does a single punch with strength mode(that has actually been removed) take all my energy while it took 10% of the suit power in nanosuit 1 and why the hell does the maximum speed feel three times as slow as with it's predecessor.
The movement felt overall clunky and not nearly as "ninja like" as it did in Crysis 1 and the prone was removed.
Crysis 2 had no destruction whatsoever except the scripted events(like that wall on the map that I can't recall)
while in Crysis you could pretty much destroy everything (punch through walls and roofs, shoot down trees, blow up buildings etc.
You just had these great moments in Crysis where you just had taken out a whole village and left tens of korean bodies behind you and you just had that moment of peace that you could just look at the sunset, see the crabs crawling on the beach and birds flying over the sky as the day turned into a night.
That being said I think that everyone that were capable of playing these amazing games fluently knows what I'm talking about. Crysis 2 has so small glimpse of the game that it used to be.
For anyone who has a gaming pc or is planning to buy/build and would like to have really amazing gaming experience should definately buy Crysis and Crysis Warhead. They are honestly two of the best games that I have ever played.
Crysis is nowadays 15$ at Steam
and Crysis Warhead is 10$
Warhead also has a multiplayer which has all size maps with vehicles such as choppers, vtols(future planes), cars, tanks, light tanks etc... and a huge variety of weapons from rpgs and orginary assault rifles to NUCLEAR weapons.

If you are lucky enough and haven't tried this game yet, you def should because it will blow your mind.
Crysis 2 isn't exactly bad, but it's something so small compared to Crysis 1.
Besides... in C1 the guy you play actually talks. In my opinion the ending scene was cooler in C2 than in Crysis or Warhead but it's the gameplay that counts.