[visakanv]

I particularly enjoyed this tetris-style game called Yahoo! Towers, which had powerups and a great multiplayer. I would bug my friends to learn to play it so we could all play it together. It was great.

Edit: Just found a video: https://www.youtube.com/watch?v=vwdLR-9bky4

[AndyNemmity]

I played another game like this when I was younger, it was multi player tetris with powerups, but not this.

It was so enjoyable to play, was hoping your link would be it but alas I don't think so. I remember it being a game client as well.

Edit: found it, Tetrinet!