Pretty unique, and I like it

Playing with well-marked gravity fields could be fun, but here's the thing: If you go in the editor and remove all the gravity zones, the map plays exactly the same. You don't use them in a way that actually creates interesting gameplay.

The map's lighting is not consistent with the pink background. It's so dark you can hardly even see the Refractor's paint job.

The edge of the platform you're driving on can blend into other platforms in the distance, which is not good for track "readability". Also some turns in the track are not signaled very well.

If you're serious about the performance thing, cut down on the particle effects and the number of transparent objects that overlap. Every layer of overlapping partial transparency is another layer the GPU has to calculate.

The direction of the gravity fields is only indicated with particle effects. If somebody turns off particles to improve their framerate, they have no indication for the direction of gravity.

This does not work in the default view for VR: Cockpit. VR Users and those used to Cockpit and possibly Bumper cameras will have difficulty seeing where to go.

I think the issue of performance is related to culling.