Polish, dang that's a lot of polish. The gameplay is basically just bejweled twist, with a few new features like not hitting the top and the null pieces, lots of room for more mechanics to be added. Visuals are amazing, I love the look of the game.
Found myself sometimes unable to do much with a large stack simply because I didn't have enough pieces, as well as using the spacebar to speed things up a lot in the beginning.
Overall very well done! Lots of potential here for new mechanics, since the rest of the game already seems finished.