I played a ROM of it once and realized this, but then several years later I came across it in a used game shop and had forgotten that fact, so I bought it. Oh well.
Blazingorb seems to have a nice Tetris 2 vs. game. http://www.blazingorb.com/ https://twitter.com/blazingorb https://www.facebook.com/SpaeraGame
Not true, it also has pieces that break apart, and flashing circles which clear all of the same color making the game not entirely dependent on clearing everything. In my opinion it's actually a much more fun game then Dr. Mario.