This is a Pokemon Go clone made in JavaScript and using the Leaflet library. It took roughly half a month to do, and the bulk of it was done in 400 lines of code
It has a fully functioning map, with interactable "caches" that show up in a bubble around the player. "Coins" can be taken out of or stored in the caches as you pass by them. The player can also move around the map either by using the buttons on the top left, or by clicking the top left globe button and actually moving around in the real world.
The game also stores the caches, cache locations, and the coins in the caches, so the player can leave and come back, or even close the website and open it a week later, and everything will remain exactly how they left it.