Anyone know what game this is?

[Zagatto]

That game is Tetris Battle Gai Den from BPS software and it's one of my all time favourite games ever made. I still pull it out to play from time to time and amazingly enough, I've never seen the ROM for it on any emulator sites. The thing that really sucks is that it was never released in North America for the NSES so you were playing a Super Famicom version. Good luck hunting for it.