This was super fun!
I loved how intense and fast paced it was, and it was super fun jumping focus between aiming, and driving.
The game also felt good to play. The driving physics felt really good and it was enjoyable to drive around.
Your game design is also very well polished here. I like the idea of the leaves as a means to get the player moving around the map, and your approach to a problem I saw you mentioned in the comments with allowing you to drive off the map just at a slower speed. I like that items are pulled towards you once you get close to them so you don't have to be so precise.
The uncontrollable growth theme fits in here in two ways to, with the corruption and the gigantic wave of enemies. Once I figured out how to heal, every death felt like it was my fault, like I could have driven better to avoid the giant wave of enemies.
Speaking of that, it was incredibly fun to drive tactically in order to avoid an unwinnable situation. One time I lost because once the timer ran out I just made a b line for the station and ended up being completely surrounded and unable to move, so it was fun to have to drive in a way to avoid that. I didn't stop playing till I beat it.
I don't know if you drew all of the art, but the art looks very nice and cohesive. I just wish the bullets were a little bigger. I'd say the outside of the map should be something else though, instead of gray. Maybe the dirt sprite, but darker, and zoom in the camera so it's clear that you shouldn't be here, but it doesn't look like a bug.
My only negatives for the game is that it would do good to have more feed back, the menu moves really slow, and the game seems unoptimized for starting?
For feedback, it would be nice if the car had some sort of effect when it got damaged, maybe just a white flash or a damage number. You have screen shake and a sound which is good. Same thing for healing. Maybe if the car became more scrappy as it got damaged, and it was all healed when you press E.
The buttons need to have hover sprites, something that indicates its registering that I'm going to click it and that when I click it, it did something. That would allieviate the issue of the next problem.
This game doesn't look like it should take that long to start up. Whenever you click restart or start, the game freezes for like 5 or 10 seconds before loading it. I often did not know if it worked because theres no response on the buttons.
Last issue, the fading transitions in the menu need to be way way faster.
Overall though, amazing game, I really enjoyed this one and had a blast playing and beating it.