Sure, here's an example of a simple game implemented as a single HTML file using JavaScript and enclosed in script tags. This game is designed for smartphone operation and uses pictograms.
This game initializes with a set of pictograms displayed as squares on the screen. The pictograms are shuffled randomly on each page load. When the user taps on a pictogram, it becomes highlighted. The game keeps track of the number of pictograms the user has found. Once all pictograms are found, a congratulatory message is shown in an alert box.
Note that this is a very basic example, and you can customize and enhance the game as per your requirements.