One of the most unique new game modes is the Catch game. You control a blocky core that's slowly rising up a classic Metroid tunnel. Pieces are slowly falling from above, and the goal is to rotate the core, not the blocks, and make a 4x4 object. Once you do, you've got 10 seconds until that 4x4 block explodes and annihilates any pieces near it. So - try to make the biggest chunk of blocks around that 4x4 mess to clear as many pieces as possible.
Catch isn't online, and not being able to move the falling pieces takes some getting used to, but for anyone to do something genuinely new with Tetris at this point is worth shouting about. Will you play it more than the other games? That's questionable.
Next is the Zelda-themed Mission mode. As the pieces fall, your health slowly leaks away. To stay alive, you've gotta do whatever the top screen tells you. In the example shown above, it's just clearing three lines at once. But when you have to clear three lines using only the L-shaped blocks, things get frustrating. This one's for serious nuts, especially when you're trying to do this online. Thought you were pretty good at Tetris, huh? There's always somebody a million times better. It's quite disturbing.