The manual describes the levels that work. But I can list them here to make it easier:

Racing Levels:

Wispy Temple
Suhn Desert

Deathmatch Levels:

Snowy Pines

CTF Level:

Fire Dunes

You have to change the "level set" at the top of the menu to find the others.

Glad you liked it! Hope people start playing online soon! There are 50 ranks to achieve and full stats tracking.