I'm hoping these Nitro Kart tracks will be pretty fun with different physics, handling and some tweaks. I'm not sure what made them bland in the first place but I hope they make them more visually lively and make the music much more peppy in a way that retro remixes masters have perfected. There is some great remixes of classic game music floating around online.
Nitro Kart felt the way it did because it had really slow acceleration. Top speed was fine but it takes so much effort to get to it, and especially to maintain it. Karts felt heavier in general as a result, and a lot of shortcuts needed really precise jumps. Tracks were extremely long. Too long. The last hub world's tracks exceed six or seven minutes and the final boss track is probably the longest.