I only remember snippits, but I'm sure that the game existed at one point or another. I don't know if it was a browser game or an actual .exe file, but I remember playing it on my grandmas laptop when I was younger.
It was a Mario Fan Game/Bootleg, and it was on a semi-isometric/topdown angle, like if you angled a topdown camera only to the South. It was pixel art, pretty good pixel art for it being a non-official Nintendo IP game.
I remember it having two games, a Mario kart mode and a story/RPG mode. I can't remember the Mario Kart part, but I know that it was on the left side on the first screen. on the Right was the RPG part, where you had a small open field only going down. There was a Forest on the left side, going along the entire left end of the field, with an entrance, but I was never able to enter it. I think I needed Yoshi to enter, but I can't remember. on the top right-middle part was a Small town, only one block/space big, like the Towns in Zelda 2. I think I was able to enter it, but I can't remember how it looked like.
Unfortunately, I can't remember much more, bc I was a little kid and couldn't figure out how to progress, but I really want to play this game again, so that I can finally finish this game