This game is VERY difficult. I've been using this for a few days now and I am finding it very tricky to get to grips with. The 8 mini games are fun (although only a few use the Wii fit board) but I found myself thrashing my arms around with some of them trying to get the game to register my existence. The cardio boxing is my favourite part and it is great that you can choose to do a workout rather than short snippets like the Wii Fit (although you can choose to use the game this way too). I have two main quibbles with this game though. Firstly, is the level of fitness required. Even the most basic levels have you puffing after just a few minutes. I had to lie down after attempting the 1 minute 30 marathon! If you're not runnng full pelt (or cheating by swinging your arms up and down) the character refuses to move! My second quibble is that the routines are quite difficult to get to grips with. They don't give you long enough to get used to one part of the routine before moving on to the next. There is an option to go through the routine section by section with playback but this only seems to be available AFTER the routine and I can't see an option to then go back and have another go. Soooo frustrating. I am not a complete novice when it comes to dance so I was surprised at how difficult I found this.
Overall, if you want to work really, really hard and you are quick to pick things up, go for it. You'll love it. If you are looking for a fun and relaxed work out, stick with Wii Fit!