Sure, here's a simple game implemented as a single HTML file using JavaScript:
In this game, there is a canvas element where pictograms are displayed. The player's goal is to click on the pictogram as quickly as possible to score points. The game lasts for 30 seconds, and the player's score is displayed on the screen. When the time is up, an alert is shown with the final score, and the game restarts. The pictograms can be replaced with actual pictogram images for a more visually appealing game.