First of all, absolutely amazing that you managed to make something like this in a week. Cant even comprehend how you pull that off. That being said, heres a bit of critique. while its impressive you did this in only a week, allot of playability seems to be sacrificed for flashy mechanics and additionally said mechanics are buggy. ex: car drifting (car constantly drifts even when going doing nothing but hitting the gas). As a player I was very confused at what the point of the game was, couldnt figure out how to upgrade/make money. so I was essentially just driving around. if this was simply a test of some mechanics you wanted to try thats cool, but as a playable game I'd say work on player experience. sometimes less is more.
TLDR: tried to be a car tycoon, became car driving sim.