Have just got Wii with Wii Sports and was expecting something of the same caliber (The price should have been a warning). I have two main gripes with the software,
1. You always seem to have to have 4 players playing so if you are playing alone you are forced to wait for the 3 cpu players to take their turns. There doesn't seem to be any way to speed up the transition between players either so the whole process becomes very tedious.
2. As other people have mentioned the control mechanism is not quite as slick as games on Wii sports, eg. On the golf your swing action is represented using a power-meter rather than through your character. I found that this affected the timing of my shots which is crucial in the mini-golf.
I must admit that I got frustrated with game after less than an hour and have not played it since. I admit £10 is not much money to spend on a game but I find it hard to justify even this low price.