So I had a handful of change in my pocket and put it on the table in a stack. Then I thought about a microgame or pnp game utilizing a mechanism of removing coins from the stack.
"Quartz", Copper, Nickel, "Dimends" came to mind. But I haven't quite figured out how to make a game around it.
Here is as far as I got and it still seems too complicated or cumbersome for the microgame need I wanted:
PnP map of 7 towns, each town is adjacent to another and 1 movement space in the middle connects them so it should be no more than 2 moves to a town. Behind each town is an area to mine coins. Also there will be backpacks for your mined coins to be placed in. Only so many coins will fit in your backpack before you must sell them at a town market. If you mine a coin and it doesn't fit...you must discard that coin or another to make room!
The game will start by grabbing a handful of change and placing the stacks on 3 random mines areas of the 7 possible. They don't necessarily have to be the same height or configuration, in fact it's encouraged they aren't.
Players start in the center piece and get 5 actions per turn. Movement is 1 action per space. Now for a 2 player game one person is designated heads and one person is designated tails.
Each town will have a large market area and written in the market area are buying values of the 4 minerals;
0-4 years old
5-9 years old
Now if a stack of change is at the mines located behind a town a player may move there.
They may use 1 action to blow a dynamite, destroying the top coin and removing it from the game or they may elect to use their actions to mine up that coin!
First the player will note which side the coin is facing up, heads or tails. In order to mine that coin the player will pick it up and then flip that coin X times on the same exact side as it was originally showing.
Quartz requires 1 successful matching flip.
Copper & Nickel require 2 successful matching flips.
Dimends require 3 successful matching flips.
If unsuccessful the coin is placed back on top of the coin stack and the players turn is over.
If successful the player puts that coin in their designated backpack. Ensure that the coin is placed face up matching your assigned side to recall which side you represent.
Selling coins, at any time you may go to a town and sell your coins to that market. If you backpack is full you have no choice but to sell coins to make room for new ones! Pay actions to move to your desired town market and then pay 1 action to sell coins from your backpack to that market. Simply leave the coins (in a stack) in that market area you choose, face up that represents your side. This is important because when the game ends all market sold coins will be calculated based on heads player(s) versus tails player(s) coins.
The game ends when 2 of 3 stacks have been completely emptied.
I still feel like there is a simpler yet deeper game out there but this is what I had so far.
(The subject gave me a vague hope this might be an idea about a game based on mining Bitcoins...)
For me, part of the appeal of "coin games" is that they literally need only coins, so can be played impromptu, e.g. in a restaurant when no one brought a "normal" game. So your market display deviates from that... if there is a simple way to handle the market without requiring a separate display then that would be cooler (to me). E.g. maybe coins sit in the market and simply the quantity of each type somehow determines their price (or price modifier), or there's a line of coins (randomly sorted) and the position in the line somehow determines the price (or price modifier).
FWIW, here's possible inspiration from other coin games: Coin games
My favorite coin game is Fight!. Really brilliant simple mechanism!