A recreation of one of the basic games included in Windows 3.1. The basic rules are that the player must flag every mine on the board without clicking on it. The player gets enough information to solve this because every square that is immediately next to a mine will display the number of mines it is touching. The player only has exactly as many flags as mines. Victory is declared when all squares have been cleared except the mines.
This is part of TheOdinProject's JavaScript track. See here for more information.
You can click here to view it on GitHub Pages.