Last night, I beat the 200-line marathon mode (Type-A game) on Tetris DS
I only have had the game a week, and I beat it. It's actually the first time I've beaten Tetris, any version of Tetris. NES, Game Boy, Windows, I have never beat those versions of the game. And I owe it to playing that game, especially the marathon mode, at least once every day since I got it, just around midnight. Kinda brings me back to the old days actually, getting up in the middle of the night to fire up the old Nintendo to play a round or two of Tetris. That's probably why I was late for the bus all those times.
In beating the game, I unlocked Endless mode. I'd try it out, but I don't have that many vacation days.