Thanks anyway. It is certainly not just pressing D to beat the game, there are 10 levels. Too bad that sometimes people get stuck due to a bug, but I think I can’t do anything about it. If I can track it down, I will ask for a bugfix submission, though.
It is not much of an twist, but the tetris mechanics sets in for the columns and leaves you less and less tiles that you can put on top of each other before they collapse again.
If you don’t mind, maybe check the install version. So far I only got bug reports for the Web version. I still can not reproduce it, though, it drives me crazy!