Sure, here's an example of a simple game implemented in a single HTML file using JavaScript and enclosed in script tags. The game is a basic memory matching game where you need to find matching pairs of pictograms:
This game will create a game board with 12 pictogram cards shuffled randomly each time you load the page. Clicking on a card will flip it, and if you find a matching pair, they will stay flipped. The game is won when all the pairs have been matched.