I liked it a lot! It is a simple but very creative concept! And it was fun to play!
Some of the colleagues mentioned that a "undo selection" would be nice, and I agree! I made a "mistake" in a move and than tried to do an opposite move (like, I had 3 right, but needed only 2, so I added 1 left), but it didn't really got me back to the place I needed and the sequence failed. If these "reverse" moves were to be normalized, than the "undo selection" would not be necessary... But I believe that the undo is the easier take on the problem!
Very well done!
Keep up the great work!
Cheers!