Nice game! I have played it and while it is nice, I have some constructive feedback to provide (you don't have to implement any of this but these are just some things I figure would make this game even better).
First is the controls. They are very stiff, especially on corners. There is a game that has the best vehicle handling I have ever played on a Gameboy, it is the Japanese game "Pocket GT". The vehicle handling on that game is perfection. Perhaps having controls similar to that game would make this game so much more fun.
Second is the boost. The only visual representation of the boost are the speed lines on the sides of the screen. I would perhaps suggest saving the exhaust flames for the boost, instead of having them activate by default when driving normally. This would then add more visually to the boost and seem more like how nitro is used (emitting a flame from the exhaust).
Third is the power. I noticed when I boost, if I even make a slight bump against the side of the track or get caught against another vehicle, it almost brings me to a halt causing the other cars to zoom ahead, and I try to boost to catch back up to my place but then the power depletes and it's game over.
I might suggest that since the story of the game is that the universe you created survived an alien attack, that there would naturally be weapons going unused, so perhaps having the ability to upgrade your vehicle to add weapons/defenses and fire/activate them against other vehicles, and have power pickups that restore a small percentage of your power meter.
Perhaps also adjust it so you don't come to an almost complete halt from a single slight bump while boosting causing other drivers to zoom ahead making it diffficult to catch up.
Of course this is just constructive feedback from my own experience, and again there are no obligations to implement any of this, and I thank you for making this game exist to begin with.