A few things
This was a very nice tetris game, and I loved the simplicity of the graphics. But a couple things began to bug me the more I played:
-- In almost every tetris game I've ever played, the rotate key, when there's just one, rotates the block clockwise. This was very distracting when I kept expecting one result and getting another.
--For beginners, the current setup is fine, but in order for someone to do very well, a "next block" window is a necessity. It really adds a whole extra layer of strategy for those who know how to use it. I'm not really at that level yet.