I always said that while Natal/Kinect seems very promising at first sight, it will prove to only work well on three types of games:
- sports games
- fitness games
- EyeToy-like Minigame collections
Okay, I didn't think of dance games at first, but apart from those I consider the collection of launch titles a complete confirmation.
Thing is: I expect Kinect to be successful in games where people see a real advantage in playing games like this. For example they are trying to produce Kinect racing games, but there's simply no advantage in playing Forza without buttons but with noticable lag. People will try it out, they'll think it's fun when racing their first track, they'll start to see the problems on their second track, and they'll be using the controller again on the third track.
It's just the same problem with the Wii. Everyone was fascinated at first, but time showed that there are simply not that many genres that really benefit from motion controls.
The other problem is that due to the controllerless nature, most Kinect games require lots of body movement, a lot more than any Wii game does. People will be exhausted within minutes, and they will only keep playing if they don't care or actually want to move their body that much.
If you keep these things in mind, there are 2-3 types of games that are just perfect for Kinect: In dance and fitness games, you definitely want to move your body a lot. Kinect is absolutely perfect for a game like "Your shape". You may also like the fitness aspect when playing sports games like this, or at least you'll be willing to accept it because sports are all about moving your body. It will feel way more realistic than playing with a controller, hence it can be considered an advantage.
If you wonder why there are no games from a certain other genre - maybe the thousands of developers around the globe really simply didn't think of the genre, but chances are they actually considered them but at some stage they realized that all in all Kinect would rather be a disadvantage.