Algodoo

Here's a non-elimination-based marble race with a black background instead of black pieces. Had a lot of fun making it, and I hope this inspires more people to make custom races of their own instead of using other's pieces. Let me tell you, it's so much fun doing it this way. I tried my best to stay unique and keep everything inconsistent but still stuck-proof. The resulting course can be completed surprisingly fast, or stupidly slow. Have fun with this one. By the way I got a lot better at this game and I've aged quite a bit so there's that...

I'd bet on the white marble since it seems to win a lot.