It's honestly more suited to speedrunning than racing. There could also be finishing all mission with 3 stars and stuff. Just an idea.

I played through all 6 levels and beat them all, however, after I was done with all of them, the 7th level did NOT unlock? Help!

the exact same thing happened to me. Is there a requirement other than beating all the levels to unlock the last one?

Adding a "finish all missions with 3 stars" category seems pointless considering that star count is purely dependent on your time on each mission, so an ideal All Missions run 3-stars every mission anyways.

To unlock the 7th set of missions, you have to get at least 1 star on every other mission.

So this means I can't do All Missions runs cuz I'm a noob. Can you make sub categories for 7th level and no 7th level since its a bonus? An example of this is Mario Sports Mix. There is a bonus match, behemoth, in there and you can do it with or without behemoth

if you speedrun you should be able to get 1 star anyway, if not, just keep on practicing. There is no use in getting a seperate category without world 7 because those are already included anyway in the other runs.