I loved it.
It is quite a fun game, with very good music and cool mood.
I love the way you're teaching us, the players, new game mechanics.
Anyway, I would change some few things
The first is to make the gem fall animations a little more animated. It needs some work.
The second is that let the game detect by itself that you cannot do more moves. To make a reset by you when it happens.
The third and last is to let the game to make some move suggestions to you, when you don't move for some time.