This game reminds me of the space maps in OG Star Wars Battlefront II from the mid 2000s, I love your idea. The vehicles actually I feel different and I think they're a great foundation for a future game.
In terms of improvements, I feel like what was missing the most was some indication of where the enemies are and maybe some instruments for orientation. Battles in such open 3D environment can become very disorienting, and it's pretty frustrating to be taken out by some sneaky enemy near the end of the game.
If you add a score system and an ability to invert the pitch controls, I'd probably play this frequently in the browser.