A good version of a well-known concept here! It was fun to play and I liked the sound effects. I think that key repeat should be enabled on left/right keys, though -- otherwise you can't hold a left/right key to mean "go left as soon as I'm able to" to fit in "under" another piece, and moving quickly across the board is also harder than it need be. Holding down the "down" key does make it repeat, so I believe it's possible. But this would only improve what is already a pretty good implementation!