Ouch, out of memory error.
Edit: may be fixed in the latest GitHub release.
… unless you’ve downloaded the picosystem version, where I think I ran out of buttons.
Hmm, it should… I guess there are things that could go wrong there…
Game doesn’t even seem to load right now though.
32blit SDK, Tiled + Aseprite for the maps + map tiles, Blender and I think GIMP for the kart sprites.