If you only have a Wii you have to get it.
The game is good; that's about all. The controls and gunplay almost exactly emulate the likes of Call of Duty, but it's on the Wii so the graphics aren't as good as a true Call of Duty game. I had the most fun playing with the Wiimote and nunchuck. That being said, I wasn't near as accurate or efficient with my movements as when I used the classic controller.
The single player is definitely the better part of the game ironically. Multiplayer, while well executed, is probably as good as FPS mutliplayer can get on the Wii. The maps are alright, but they suffer from a lot of framerate drops and low quality textures.
Yes there's split screen, but it's so small and blurry you almost can't see. Not only that, but if more than one person is using the Wiimote controls it's hard to position yourselves in a way that both can be in proper range of the sensor.
Classic controllers are definitely better for multiplayer, and the players on the top of the scoreboard obviously use them, so you're at a handicap if you don't. There's not a filter that can put all wiimote users in the same game.
Also, unfortunately, with the wiimote when you zoom in you snap to the enemy closest to your recticle in both single and multiplayer. That's great and fair for wiimote users, but you also do that with the classic controller setup. Of course you can disable that for yourself, but everyone else in the game is going to have it enabled, so why would you put yourself at a disadvantage?
All in all, it's a good game; I just chose to point out the glaring negatives. In multiplayer when I used the classic controller I found myself thinking "wow this is just like CoD; awesome." We then turned off the Wii and put in CoD.
Wait for a price drop.