To use it, simply append all objects from the file into a track, position the kart by moving the "protoKart" object, and make sure that the camera behind the kart is the active one. Then, go into camera view and enter the game engine.
Controls (if implemented) are the same as the default in-game keyboard controls.
I'm not sure how useful this could be, given how easy it is to just export a track and test it in the game, but I think that this still might help in speeding up the testing cycle for tracks.
Known issues:
- Controls are snappier than in-game
Camera is fixed
Gravity isn't completely identical to in-game
Skidding in mid-air is different from in-game
Acceleration is the same no matter what the current speed is
Going up hills is slow
Turning radius is only identical to in-game at 21 m/s
Kart doesn't align self to terrain
Kart bounces when going downhill
Controls aren't reversed when going backwards
Crashing doesn't reset momentum
EDIT: Uploaded new version with improved handling and camera