Hard at first, but once you get the control scheme, you will like the game. Unless you are a 360/PS3 fanboy that is...
Many people will say that this game is broken, but that is because they aren't good at the game and don't know how to be good. This game is easy once you push past the lag, glitches, hackers, and noobtubers. Here is a rundown of all these things...
LAG:
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Lag is a feature in every online game that makes it so you can not shoot "right" at the opponent to kill them. In the wii game, the lag is more significant than in the 360/PS3 versions. This is easier to cope with though, with the technique of lagshooting. Lagshooting is where you shoot slightly in front of the target depending on how good your connection is(ex: 3 bars=little lagshooting). This only makes one type of gun hard to use: the sniper.
Glitches:
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Glitches is where people find flaws in the gamecode and take advantage of it by finding out how to get out of the map, float in the air and run around on it, and so on. This doesn't influence the game too much in my opinion, since you most likely will be able to shoot them down still.
Hackers:
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Hackers are people who "hack" the game code to be able to cheat at the game. These cheats include:
-Invincibility
-Invisibility
-Moon-Jumping
-Infinite Ammo
-No reloading
As you can see, hacking is one of the worst problems in the game. For me, I rarely run into hackers, so I don't find it as much of a problem. A simple solution is also to just exit the game.
Noobtubes
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Noobtubes, also known as the grenade launcher, is an undermounted attachment for the Assault Rifles. It really isn't that cheap, but people overuse it with a perk called Overkill, which lets you have 4 grenades instead of 2. Little kids usually use these when they are mad that they are losing, so they use them all over the map, which makes the game unfair and almost unplayable. Again, you can exit the game, but sometimes, it is better just to deal with it because your next match will most likely have them in it too.
Lastly, the single player is short, and very repetitive in my opinion. But I only bought the game for the multiplayer, so I don't care that much.
Overall, this game is quite fun, once you get past those obstacles, and I liked it all the way until now, which is the end of my MWR career, where i trade it in for credit towards the next game, Call of duty Black Ops. I hoped you liked my review, and good bye.