I built an arcade machine from scratch (MAME for arcade games) and had a coin button to begin with. Mostly meant that it was too easy to just spam the coin and start button (besides one another) and just “pay” our way through games.

I built coin slots with tokens falling through a light sensor and now it is a little more work to “pay”, and also a slight shame introduced to the gameplay when your pile of tokens are significantly smaller than your friend’s :)

We’re trying a little harder now to play better.