I find the concept very interesting. However, I feel like it is missing a lot of things.
Like others said, it has untapped potential. I think it needs more upgrades (stronger link between the cars? Barriers that prevent the gold from falling off?).
I also think it needs some sort of change between the sceneries (one map snowy, another map rainy or sunny etc.).
The music was perfect and it really represents the whole idea.
Overall, think about what needs improving and build on it.