The official game provide 9 tracks : there is 3 environments, and 3 levels of difficulty. Once you know the game, it's quite limited. Thankfully, the game contains an editor, which is activated by the cheat code "aja". To open the editor's menu, just press "e" while you are playing.
You can check the video tutorial, or the text tutorial. For a quick reference, you can look at the Quick Reference Guide. With this tool, some users created some tracks. You can find some of them on mk's website.
I have created several tracks. My oldest ones are the following, available in the Xinfepack:
EnterTraining
Xinfe-Duo 1
Xinfe-Duo 2
LearningMap 1 (or Highspeed 1)
LearningMap 2 (or Highspeed 2)
Years ago, I started a project of providing many tracks on a single piece of land, similar to the game (almost) uses the same land for the Alpine and Forest environments. The project was forgotten and then resumed in 2019, but is now available to download!
New Alpine Easy
New Alpine Medium
New Alpine Hard
New Forest Easy
New Forest Medium
New Forest Hard
New Village Hard
New Practice