Simple yet addicting game. The game mechanics were somewhat... way more concealed than what was necessary. I spent no less than 5 minutes clicking all over the screen, trying to figure out what the hell made the elements drop, so please just include a tutorial screen of sorts for first-timers so don't storm away feeling puzzled and/or angry.
Anyways, onto the gameplay itself. First off, if you're looking into future additions, please for the sake of all gamers out in the world add a restart button. Refreshing the game is really really frustrating. Secondly, The idea, while not completely unoriginal, is still quite an eye-opener. That said, however, the one major flaw I see in your game is the seemingly random placement of the transmuted element. More than one time had I set up a perfect drop triggering a three-stage transmute only to find a leaf someone got in between two of the green dragon plates. Please set in a fixed system of locating the end results, please. Lastly, the controls were... eh. If possible, try to institute a system where turning the blocks as well as move/drop are located on the same hand, i.e. both mouse or both keyboard, because I found switching back and forth between arrow keys and clicking to be somewhat annoying and took away from the enjoyment and thought processes of this potential-filled game.
Overall, well done, keep it up.