Good question! Let me consult the pile...After a bit of research, It's Super Mario Land which released on the Gameboy in 1989! I got mine used at some point, probably from a flea-market or something. I have neither box nor manual and even though I did download it on the 3DS, I do own and use the cart on my GBA-SP. I also have and play around with many Super Nintendo games which would be runners up depending on the titles.