Looking very cool! It seems like the torus wireframe fades out a little bit abruptly.
One thing that might be neat to try is to have your own bullets (or maybe only missiles or something) travel far enough to wrap around the narrow axis and become hazards. I did this in a jam game set on a snake shaped torus, and after you have enough powerups to be firing quickly, your own bullets can be as dangerous as the enemies 
(such bad art, so placeholder sounds, much game jam rush)
Cheers,
Noland