This game is definitely one of the best games of the year.  The shooting is smooth, the controls precise, the graphics are beautiful, and Infinity Ward is the king of shooters.  While this game lacks in innovation, it makes up for it in polish and solid gun play.

Single Player: Aye, the campaign is SHORT, but I think that it is one of the best I've played.  The while the over all story doesn't do much, each individual scene captures a mood.  Especially the level "No Russian" which is my favorite part of the game.  The moment you first walk out of the elevator and you fire into the crowd is jolting and way more terrifying than space zombies.  The action is also amazing as each level is unique and forces you to change tactics.  The game is also filled with breathtakingly awesome set pieces, from climbing up the sheer face of a mountain with you snow pick, to a trilling chase were you have twenty seconds to jump to a helicopter off the face off a cliff as enemies surround you and shoot at you, to sniping in a moving helicopter, and rappelling down a cliff. While a lot of people may complain about the length of the campaign, at least you get more time for...

Mulitplayer: Which is addicting and awesome.  Online is fun, and the deep leveling system is going to keep you playing this along time.  You can also create custom classes to use in combat, and with a ton of combinations available with Perks, killstreaks, Deathstreaks, and weapons and weapon attachments.  Deathstreaks are a welcome addition for those you suck at shooters and get killed a lot online.  You can copy your killer's class or get a needed health boost which has saved my back a lot online.  Modes range from team Deathmatch to Capture the Flag, Domination, and my favorite, Ground War.  Ground War allows for up to 18 player Deathmatchs or Domination games.  Multiplayer is cool even though not much has changed from COD4.  But if your wanting something new, try...

Special Forces: For it is most fun.  Especially with a Co-op buddy.  You can play Co-op online, but I recommend getting together with a friend in your living room.  Nothing beats working together with a friend to kill stupid terroists.  Special Forces mode is pretty much a collection of missions that range from excerpts of the campaign to original missions.  This mode is just as action-packed as the campaign, but you don't have to worry about a dumb story or length, because the content here is more than that of the single-player campaign.  Missions may range from fighting waves of enemies that get tougher each wave, to eliminating Militia fighters spread across a map, or stealthy sneaking through enemy territory.  One of my favorites is when one player is in a plane as a gunner as a second player is on the ground, and the player in the plane must fire down destruction on bad dudes and escort the player on the ground to his objective as the player on the ground marks targets for the player in the plane to destroy.  Special Forces is going to keep you hooked.

Overall:  While it dosen't do much to innovate on the COD4 formula, Modern Warfare 2 is just as great as the original, and in my opinion much better.