http://www.digitaltrends.com/gaming/mario-kart-xxl-prototype-discovered/ So apparently a company called Denaris Entertainment Software either was working on, or at least pitched, a Mario Kart game for the GBA. There's video in the article I linked. If it is at all real (which I doubt), I'm pretty certain that it was an unsolicited pitch, because Nintendo rarely lets companies use their IPs, and certainly not relative unknowns like Denaris Entertainment Software (Mobygames has 5 games to their credit, 2 DS shovelware games, a GBA pony game?, and a couple PC/PS1 games). Plus Nintendo hasn't released more than 1 Mario Kart game for a system, ever. But I really don't think it's real, just going from what's in the video. The resolution looks a bit higher than the GBA, and I don't think, even near end of life, it was capable of Mode 7 scaling, multiple layers of Mode 7, and transparencies simultaneously. What do you think?