Very cool mechanic! Interesting how you have to make a tradeoff to get the points, but that slows you down. It makes for some interesting decisions about which coins you bother grabbing, and which paths you take. Also some interesting level design you can do
Feedback: It wasn't clear to me if the upgrade selection I was making was actually taking place as expected -- maybe a little animation or seeing a number go up after making the selection would help with that