The environment and the sound is fantastic! I will recommend you 2 things to make it better.
A easy version mode where you can play with one botton that acelerates and one to go to the rigth and one to go to the left.
A hard version mode where the controls are exactly as you have now.
The second thing i recommend is a splitscreen or multiplayer mode.
Overal excelent game! Hope you continue with this project.