Fun game but an impossible situation where there is a car on every lane appears pretty fast. Maybe fix it by checking if there is an empty lane before you spawn a new car and always have an empty lane.
Really fun concept, it doesn't matter that you're only on one level. The random spawning of the enemies is a bit annoying tough. Maybe make them spawn outside the field of view and enter from the sides.
I think the instructions are not super clear, that might be because english is not your first language. But the concept is cool, maybe give a bit more time to look at the level before you have to decide if you want to start with holding a key down.