Samba de Amigo is a blast to play, but its broken controls on the harder difficulties make it hard to recommend
Sega did a lot of things right. For one, the track list is outstanding, and really sets it apart from other music games. The visuals are bright, colorful and highly polished. There's also a great sense of humor that permeates through the game. It also has one of Sega's coolest characters--Samba the Monkey.
The problem is the controls. On the harder difficulties the controls are pretty much unworkable, and the game will often misread your motions, or disregard them altogether. It's not totally impossible to get them to work, but your moves have to be incredibly deliberate, and there's no room for error. Playing on Super Hard is like trying to rub your belly and pat your head at the same time...while playing the maracas.
The multiplayer is a lot of fun if you've got some casual gaming friends who don't mind playing on "easy" and "normal" difficulties. If you're looking for a hit new party game, Samba is cheap, and the multiplayer is a blast. But the single player offering is pretty shallow and gets old quickly.
Samba had so much going for it. And maybe when we get the WiiMotionPlus we'll see a proper sequel so we can play the game the way it was meant to be played. But until then, I suggest you stay away from Samba de Amigo.