The plot was incoherent and disconnected from reality, the gameplay was a tortuous and repetitive game of blood-spattered whack-a-mole, and none of it had the visceral awesome punch of MW1 levels
(although there were a few excellent sequences, including Ghost and Roach's death, the assault on the oil rig/prison, and the very last quick-time event.)
But whole levels were simply plot holes (who was the tattooed man in the safe room? A Russian mobster? Why should we care?), the 'No Russian' sequence I was so excited about was simply gratuitous, the main, er, threat to America was completely preposterous
, and they gratuitously killed off the ISS and its crew for no reason whatsoever.
It's as if they came up with a series of cool movie tributes to do and then strung them together.
Also, for ****'s sake, that Favela level was irritating.