Great fun to mess around with for a bit, although I didn't bother trying to figure out the O piece one. I think it would work really nicely with some little achievements to accomplish to "beat" the game. And a high score tracker for each mode. Not sure how doable or worth that would be for this jam.
Unlike the first comment, I had no issue with the DAS and ARR because I usually set my DAS pretty low and ARR to 0. But I remember how hard it was when I first started playing Tetris, so I feel their pain.
The menu was very creative and the different games were interesting. Felt a bit like trying out different games during a jam. A game jam experience inside of a jam game.
Great job!