Took me a long time to understand what to do. I was placing random boxes and they were just floating upwards every time i started playing. I was only after reading the comment about "line rider" that I understood that it is the little green thing that is the car, and that it is actually falling down! Then I started adding boxes under the car, and things started making sense. First I thought the boxes I was placing was the cars, as they were the ones moving. 😅
You don't explain anywhere what is actually happening and what we are meant to do. When you don't have time to add such explanations in the game, just write it in the itch page instead. :)
A simple way to make the player understand that we are falling is to have an image/texture in the background. Then we can clearly see that we are moving. Also, if the small brick is supposed to be a toy car, use an image of a car! Just drawing on some wheels would do a lot! :D
There's nothing to really achieve here, but it's a cool concept, and you could potentially make this project into a proper game later by adding some objectives.
I don't see that it fits the theme though. :p