After completing the single player campaign on Veteran, getting to level 70 in multiplayer and trying out the special ops mode I have come to the conclusion that Modern Warfare 2 falls well short of the original game. I don't think the game is bad, but it does not even come remotely close to meeting expectations and hype.
Here are my reasons and complaints:
Campaign is shorter and not nearly as epic and fun.
Multiplayer maps are horrendous: bad design, most too large, almost everywhere on the maps you have to watch your back from 10 different directions to avoid getting snuck up on.
There is a lot of problems with matchmaking not working properly. Many times it takes longer to get into a match than it takes to play it, plus the teams are almost never balanced and almost every match 1 team is outnumbered.
The weapons are very inconsistent with how they work. One kill you hit a guy once and he drops and the next you hit the guy 10 times and he lives. I have seen people take direct hits from RPGs and live.
There are too many aerial weapons where one team can have a chopper, UAV, harrier all at the same time. Then if there is an AC130 you basically have to stay indoors to have a chance at not dying. Also, the aerial weapons quite often target a single target way too many times. There are times where I die to the same aerial weapon 5-6 times in a row, which includes me trying to shoot the damn things down with them always getting me right before I launch my weapon at them.
The host based system is poorly implemented and many times the host has the absolute worst connection out of everyone causing major lag issues.
The knife is horrible compared to the first game: it takes too long to come out, too long to be put away and the button is way too sensitive. Many times I get random knife draws when making a quick turn even though I did not press down on the button at all.
There are way too many attachments for the weapons, half of which are pointless for many of them. There is no reason to have a red dot sight and a holographic sight as there is not enough difference, plus I am finding the red dot sight that you get first is a little better overall.
The heartbeat sensor is the worst idea I have ever seen for a shooter. There is no such thing in real life, and I see way too many noobs camping with it and just waiting for people to come by and knowing exactly where you are at all times.
Overall Modern Warfare 2 is a good game, but it is not game of the year, and not better than the original. I am already tired of playing the game after only a couple of weeks and am very disappointed.