The single player is probably the strongest mode this game has to offer.
The multiplayer both online and splitscreen is for the most part exactly the same as the first game, just new maps and some new guns. The guns are still inacurate and the gameplay still has the same holes. Although they did try to fix the inconsistency and inacuracy, the problems are still noticeably present, just not as much as in the last game. The online multiplayer still has the same community as the first. One sentence sums it up: People take the game way too seriously.
Spec-ops mode is the only split-screen coop mode in the game. While it does prove to be fun enough for only a single playthough, it provides nothing more. If you've played Campaign for a little while, spec-ops will not give you anything new. It is only good for one playthrough but after that, it becomes repetitive and boring.
As I said in my review for the first Modern Warfare, gameplay flaws are what kill the game. This time though, the poor coop mode and worsening online community have a bigger hand in bringing this game down. The amazing campaign mode is what makes me give the game a better score than the first one.