This is an interesting and original concept. However, there are quite a few unnecessary things here that might frustrate some players.
1) Maybe don't play the starting dialogue every single time somebody respawns- especially in a game where one dies quite often! Same thing with the menu screen- once the player dies, why do they go back to the main menu screen? It's not like it offers another mode or something, and even then, like I said, the player dies way too often to have to do all that again! Also this is literally a nitpick but once the player clicks the "Play" button, why is there another "Start" button the player needs to click after that to actually start the game?
2) The collider margins between objects seem pretty inconsistent with each other- it's quite easy to pass between a narrow space between two rocks, but not where there's a tree. This may just be because our brains think the collider margin should be limited to the stump/bark only. Consider reducing the margin for trees.
Also I'm not putting this in another point as it is quite literally a pretty small nitpick, but because we never see anything of the front of the car, it feels like we're always driving straight but the camera is facing the other way.
However, if I seem a bit critical of this game, then just know that I enjoyed playing the game! The reason this review seems a bit critical is because this game had quite a bit of constructive feedback it could benefit from.
All in all, it's a pretty fun and unique concept!