So as far as I know, it's a bug that happens but I have no idea why. Have you found out a way to make it happen consistently?
It usually happens when I get a high enough score. usually, at that point most of the blocks falling are bricks. All the enemies have stopped moving ( either from lag, poor computer wifi or the more probable answer, the quicksand ability assuming that it stacks) (I also usually have most of the ability and as far as I'm concerned it doesn't have to do with curses.