Minesweeper: Find Bombs

Minesweeper, the one from the office computer, rebuilt so that it runs in a browser tab without asking anything of you. Open a cell and it tells you how many mines touch it; flag the ones you have worked out; clear the field without opening a mine. There is nothing added, no story and no timer pressure beyond your own, and that is the whole value — the deduction is the game, and it has held up for thirty years. Levels get larger rather than cleverer, which is the right way to scale this.