Annnnd three years later I actually play through Crysis 2 Maximum edition. It runs decently now with some computer upgrades.
Overall I think that the gameplay is more rewarding than the first Crysis game. Fighting random terrorists in the jungle is not as rewarding as going directly from oppressive private security to microwaving alien squid in their armor. Oh yeah, spoiler, the microwave gun is that friggin' awesome!
The flow of the single player campaign was even. I felt like it was not too short of a game, but not tediously long either. The variation in enemies, weapons, and combat situations kept the gameplay fresh enough to last through the campaign. I have heard little on Crysis 3, but definitely favor Crysis 2 over the first game or Warhead.