FloboPuyo 0.20 is a curious tetris variation with round bubbles in place of the classic blocks which you must group by colour, and the most interesting part is that on the other side of the screen is another player (the PC by default). They play the same pieces, and each time you eliminate bubbles, they appear on your opponent`s side, complicating things considerably (and, of course, they will try and do the same to you).
Obviously, the winner is not the one who makes the most bubbles disappear, but the one who makes their opponent lose by filling up their screen.