It took me a few tries to understand how to use the boost mechanic.
I read too fast and only understood that I had to put tomatoes into the box, but somehow skipped the part that I need to CLOSE it. Definitely would help to have a popup on the first level pointing at the box and saying "CLOSE FOR BOOST!" Once the player has learned this, the other levels don't need it.
It also took me a few tries to understand the right timing to boost during the boss fight. I went for a while thinking it was an endless fight and that the boss HP would never go down. I eventually got him though!
I think the part that I didn't like much was the engine noise. Without much to slow down the car, the sound is just a constant noise that doesn't go away during the whole gameplay, which gets a bit annoying. Other than that, fun game!
Good work, team!