What is it with Ubongo?
This is easy to explain, because you have to try to put on a surface with a given field-shaped parts so that the surface is completely covered, thereby projecting part on the surface without. For the special flavor ensures that you only have a certain amount of time to accomplish this task.
What now sounds quite simple, is some (although the angular parts can not be far put as heavy as the honeycomb parts of Ubongo EXTREME - which I personally prefer) times really tricky. Ubongo now is also the smart phone route and provides an app ready, with which you can stop the time, while the younger players can be considered (which I personally find class.
CONCLUSION:
Ubongo a lot of fun, even if I normal Ubongo almost too easy (for me) find (as I said, I prefer Ubongo extreme). If you Ubongo however also plays with children, the normal variant was good enough and the app can be time well such that the normal version is a challenge for young and old.