Love me a sorting puzzle game, and this one hits the spot. I will echo the up/down movement issue that others have mentioned; in addition, I think a few of the colors are a little too similar, which did give me some grief. It did *seem* like they were a curated palette, but perhaps a bite more curation (or a high-contrast option) could be helpful. That said, the shadowed blocks are a really neat touch and add just enough spice to the classic formula to make it tasty.
I think I might've liked a timer (maybe one that just shows the completion time, not one on-screen and visibly counting up) or maybe a move counter?
Overall, very nice!
