Simple yet attractive

This is very simple exercise having only seven notes. And seems simple with good background clouds moving (:)). I have tried other software. They have different options available there but still I usually give up after 15 min feeling monotonous. But with this I am able to work on very basic ear-training for more than half an hour now. This may not be useful for serious ear-trainers but really good for beginners like me. Feel that this would also be good for kids to introduce them to music notes.

Malay Das about Music Cubes