Thanks! I'll have a new update soon with a new HUD and more stuff. I'm working towards getting a playable demo out.
And yeah, game design is all about iteration. You can't just make everything all at once. You need to build something, then evaluate it, then add something, then see how they work together. Then, try experiments. Then, once you get things looking better, you can start getting everything to look right. It takes time. Plus, a game should evolve as you test it and see what works and what doesn't.
Anyway, I tried your game real quick. I'm not really a cell phone gamer, so my opinion isn't going to be worth much as far as rating the game. It looks cool so far. I admit, it's a bit much to take in at once, I was just expecting to fire it up and start racing, but there was quite a lengthy tutorial. Which will be fine for normal players. I just don't have time to really learn a game and evaluate it at the moment.
Have you considered using something mimicking paddle shifters to change gears. Just click the left one to gear down, and the right one to gear up. Seems like it would be easier to see on the fly. I only spent a little while with the game, so forgive me if you already had an option for something like this. Also, I didn't play long enough to get good at it, so this is just a quick thought.
Maybe also add a sound effect when the ship explodes. Again, I don't know how far along you are or if this was something you had planned. You should probably add a game build summary when putting out a demo so people know if something is not yet added or placeholder or whatnot.
Other than that, it looks cool. I look forward to seeing more.