This is a cool angle to the idle game world, and interested to see the final product.
Had some thoughts to throw your way:
* When hovering over a coin or upgrade to purchase in the right panel, I would like the information about the coin/upgrade to be visible much closer to the item I am hovering (instead of the bottom left). Like a slide out maybe, or the lower right? Personally I don't mind if it temporarily blocked some of the play area while looking at buying coins/upgrades.
* Would be great to have more info about what coins are currently worth when hovering over them in the purchase panel. For example, if I have several upgrades for a copper coin, it would be helpful to see how much per successful flip a copper coin is worth while debating investing in more. I know I can monitor the play area to figure it out, but a nice-to-have when figuring out how to be efficient.
Good luck, and thank you for the game!