The Wii version's use of the motion controls feels comfortable, but seasoned players probably won't find anything particularly compelling about the setup. Younger players, on the other hand, will find it really easy to get into and should have more fun with it.
Waving the Wii-mote in different directions produces different attack types. A quick waggle to the left or right is a quick attack while moving up will knock enemies into the air. The controls are responsive and don't take much movement to get a response - so while you do a fair about of flailing around during gameplay, you will not wear yourself out.
The Nunchuck attachment is used to move as well as unleash a special wind-up attack. Shaking the Nunchuck begins a wind-up; the longer you shake it, the more powerful your punch gets. At least, that's the theory. Winding up for a powerful punch leaves you a little too wide open for attack, so the set-up usually ends in a cheap hit from an enemy rather than a big hit. The times it does work, it isn't any more effective than a quick combo or finisher.
Enemies drop fairy dust when defeated that will let you pull off special moves. Hitting (C) when prompted pulls off finishing moves that are specific to each character. Shrek will pick up enemies and pound on them, while Puss uses his trademark "sad eyes" to stun enemies and get in a cheap hit. After accumulating enough fairy dust, hitting (C) and (Z) together activates a powerful attack like Shrek's Ogre Rage, which slows down time and stuns everyone on the screen for a short period of time.
As a game, is nothing special. There's a noticeable lack of polish and sometimes the game is a little too simple. At the same time, younger players who just want to play as Shrek should enjoy the ease of play and simple design. So to that end, Shrek the Third is a fun diversion for younger players but nothing seasoned players will want to check out.