The visuals aren't impressive, but they're functional and the frame rate is steady. When you aren't too busy rocking, you'll see that while the virtual band that rocks in the background looks pretty cool, they're nothing more than footage of prerendered characters. They don't react in real-time, and because there's only one pre-made video for song, you'll tire of seeing the same routine repeatedly. It's too bad, because seeing your customized characters own the stage was a blast on the 360 and PS3, and it was amusing to see the goofy photographs of your band in the load screens in those versions.
But it's not that important for a music game to look good; it's supposed to sound good. For the most part, Rock Band sounds terrific. The cover songs are generally very well done, and some of them, like "Train Kept a Rollin," are amazingly true to the original. If you don't have a stereo hooked up to your Wii, you're missing out. This is a game that's best played loud. The only (minor) gripes are things you probably won't notice if you haven't played the Xbox 360 or PS3 versions--the crowd is lively but doesn't sing along, and the effects that you can use on the guitar during solos and overdrive don't sound very good (though the normal guitar sounds just fine).
It's always the drummer's fault. Always.
Thanks to a lack of online play and a stripped-down feature set, the Wii version of Rock Band isn't the best one available. But that doesn't mean it's not a great game; it absolutely is. Whether you're a lone rocker or have more band members than Parliament Funkadelic, there are dozens of hours of entertainment to be found here. Short of signing with a shady manager, developing a substance abuse problem, and dying tragically young in some sort of transit accident, there's no better way to live the life of a rock star.