Kirby Squeak Squad
The World Ends With You
Puyo Puyo! 15th anniversary
Luminous Arc
Bomberman (the first one, for multiplayer)
WarioWare Touched!
^the games I play the most on my R4
bold means it's extra good
I actually haven't played any Puyo Puyo games before this one, and I just started playing this one a couple days ago. I ended up really liking it so I googled for a translation.
I was filled with joy when I found this.
I didn't know they made an MSU cart for the Genesis.... I knew about the SNES one and the library for that is rather large but the Genesis one has very few games