Meh, it's a Cry game. Farcry, Crysis... they all play identically, the only difference being your toybox. Crysis 2 ain't guna blow the world away with any of its gameplay, but it works well enough.
And it has an invisible mode... which cuts out the most annoying thing in every one of the Farcry games. "Hey, how ya doing?" "Oh, I'm fine, just... Bob, stay perfectly still" "Huh? o.O There a spider on my shoulder?" "Theres a dude in that bush, about 3 miles behind you" "Well, lets go kick his ass! >=D"
None of that here xD it actually reminds me of Arkham Asylums stealth challenges at time... you get spotting taking a soldier down, you sprint away, disappear, climb up and wait for the soldiers to stop unloading at your last spot and go check it... slip behind, knife the last guy, unload your silenced gun into their backs, disappear... appear behind last guy, throat grab, throw off balcony.