Great game! The feel, the presentation, and that loop of tetris music is really catchy. I guess the only gripe I have is that the difficulty dropped off at some point. I was sorting blocks to players and seemingly could go on for ages. Dynamically adding more players, or random blocks of no matching color or ramping up the speed, might help achieve a more satisfying ending.
It's weird now that I think about it, that having to stop a game, because you don't die and "fail", is less fulfilling than actually dying...