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.