I really like the music and graphics here. As for the game play, it didn't feel like there was any strategy involved. In earlier levels you could try to form bigger groups with strategic clicks, but in later levels gems come so fast there's not enough time to think. Then again, I was just randomly clicking them the whole time so what do I know.
Also, I suggest you add hot keys for the power ups: it takes too much time to drag them in later levels where you actually need them.
 "GemClix Blitz"){kind=icon}
 "Remnants of Skystone"){kind=icon}