1) It is fun to compete against your friends/family. 2) It is fun trying to break your own records in single player. 3) I have 2 sons 7, 4 1/2. Both like the game. The 7 yr old has more success across a wider variety of events. The 4 yr old has found events he can be successful at. 4) You can play as your Mii. That is fun. 5) Graphis - okay. I have 50" DLP TV. Mostly good, some jaggies, though you don't notice this during the events because you are too busy. 6) Its you against the world on the online leader boards. You can scroll though every score uploaded, see the top 30, or see the few around your score (and see your exact rank in the world). You can not limit the leader boards to you and a few friends who also have Wii. 7) When you start the game you type in your name. All records uploaded to the online leader board take this name, even if the record was set by your friend while playing a multiplayer match. Thats kind of annoying since we have 4 people playing all together, but all are leader board entries say my oldest son's name, even though they aren't all his records. They do get the correct Mii picture beside them if you set the record with your Mii (as opposed to a Mario/Sonic character). 8) Sonic can't swim? He wears a life jacket when in the pool and runs along on the bottom of the pool. That's odd.
Overall: I really like the game. My kids like the game. My wife is even playing (first time since Wii Sports).