Okay, so A few things that could improve this game:
1. The Assets of the Trucks, both your's and the enemy's are Very small, A size increase would be a good thing for this game.
2. The player vehicle feels very sluggish, making it more nippy would be good.
3.The enemies feel like they have way more of an advantage than they ought to. Restricting them to the same non rotational two axis movement the player is stuck with would make them feel much less cheaty.
4. The lanes don't fit the vehicles, a simple resize could fix this. you could also make it so there is on coming lanes.
5. There feels to be very little in the way of progression, levels perhaps?
6. Now your sound design is actually pretty good, but I would add some sounds to show acceleration, and deceleration, along with swerving side to side. Oh and more punchy shooting and enemy death.
Good effort though, hope you continue to make games, and continue to improve.