This is an Elm implementation of a memory game that chimpanzees vastly outperform humans at, see https://www.youtube.com/watch?v=ktkjUjcZid0 :)
There are two versions, linked are Ellie sessions where you can try them out and edit the code:
hide-after-delay
hides the numbers after a fixed amount of time, adjustable with a slider. Young chimps can go down to 500ms here.hide-after-first-click
hides the numbers only after the first click on a number.
This Elm code was quickly hacked together and can certainly be improved in a number of ways. Use it for inspiration, not for reference :D