A koopa race category could be a good and fun category in my opinion
I was thinking of doing all competition moons (called all competition moons because you can compete on ingame leaderboards for a top spot) where you get all moons that have a leaderboard with them including volleyball, jumprope, bound bowls, rc car, and koopa freerunning
I would have personally said all score minigames, including Tracewalking and Face Replica. Or all races/Koopa races
I think my idea would be that you do all koopa races, and add the times you got up. Meaning you really just need to upload the screenshots, so anyone without a capture card could play. (Or at least make a video of when it gets to your time so there'd be less chance of someone cheating.)
Umm, uploading the screenshots would not be single-segment. You would have to do the races in a single segment, and each one (except for the first) first try