There‘s also an excellent Gameboy Color romhack of Dr Mario that supports multiplayer. Recently tried that out with my girlfriend and it was a lot of fun.
Edit: this is it for anyone interested. Looks like even the original version for the Gameboy supports multiplayer.
You could play multiplayer Tetris that way. I think I saw it once in my life.
Me and my brother did it on road trips in the family van. It was awesome.
There‘s also an excellent Gameboy Color romhack of Dr Mario that supports multiplayer. Recently tried that out with my girlfriend and it was a lot of fun.
Edit: this is it for anyone interested. Looks like even the original version for the Gameboy supports multiplayer.