The second game was pretty forgettable. This one more than makes up for it. Got a good story with familiar characters and more references from the first game (still one of the best sci fi shooters ever made in my opinion).
Although i was disappointed that its basically Crysis 2.5 in terms of the way it looks (UI, gun models, horrible console FOV etc..) the graphics are definitely something to talk about. Crytek still reign as the best in that field and probably have the best engine a game has ever had. Here on PC it's pretty much the best experience you can have with it.
I cant really comment on the mulitplayer side as i dont really like playing online. The single player is quite gripping with fantastic cutscenes that keep your eyes glued to the screen. Its alot more wider than 2. Offering you more room to manoeuvre and explore. It also offers a couple of larger open areas you can drive around in like the first game.
Main gripe I'd say was the length of the game. Its a little short in comparison the last one, but that's to be expected from modern games i suppose, as most of them are. Unless you're playing an RPG or something.
Give it a go if you liked the first and Warhead. you might be surprised.