Really fun entry, had some AWESOME music, good job!

The artwork is good and the driving/drifting felt really good (at least in the starting gear). Overall wonderful job and keep up the hard work!

Recommendations:

• Switching Gears - This was quite frustrating. If you intend to keep this game based on a single input (LMB), you can try letting the player double-click to switch gears/boost.
• [R]estart Button - Many times, I would try to change gears, only to be blasted in the wrong direction. Having a restart button would have helped make this a little more manageable. This also shouldn't conflict with the theme since the Restart button has no gameplay influence.
• Checkpoints - These need to be large enough to cover most of the lane. If you emphasize "short cuts," then this actually hurts the game quite a lot. You should never give the player a path that would prevent them from meeting with a checkpoint, instead create shortcuts that diminish the time between checkpoints and force the player back into the lane.
• Level Progression - If you have to unlock levels, please save that information; otherwise, just make all of the levels available from the start. There's no reason to prevent the player from checking out level 3 even if they were unable to complete level 1/2. It is just a game jam, let everyone see how much work you put into it!