Wow, that sure is an ugly prototype! :-)
No, seriously though, very cool to prototype the game to get a sense of its gameplay first. I think it's a neat concept: on the first round I was like "uhh...so I roll dice?", but by the second I was considering the dice and the cards and thinking "this isn't trivial, is it".
I ended up six coins short on the fifth round, which isn't a bad showing, all things considered. I did feel a certain lack of control; the rule "larger divided by smaller" felt particularly hard to manage, since even with a d20 (do they go larger?) and a d6 (do they go smaller?), the expected payoff is pretty small. (4.5ish, depending on how you round, with better than a 50% chance of getting three coins or less.)
But it's intriguing! I'd love to see where it goes.