Love the game! Just one minor bug:
when using Arrow Keys and N for nitro, I can't turn left. WASD works with N or X, and Arrow Keys and X does also work. since the help calls for using N with WASD, I don't think a lot off people will have this problem :)
for lvl 15:
I managed to hit three planes at once, with rocket full upgraded directly over the train, then bombed the cars left and right of the phone booth -> 7 explosions
 "Neon Race 2"){kind=icon}
 "Mass Mayhem"){kind=icon}