Sure! Here's a complete working endless runner game implemented in a single HTML file using JavaScript and enclosed in `script` tags. This game assumes smartphone operation and uses pictograms where possible.
This game sets up a simple endless runner environment where the player (orange square) moves upwards when the user touches the screen (assuming smartphone operation). The player's goal is to avoid obstacles (red squares) falling from the top. The game keeps track of the score, increases the game speed over time, and displays a game over message when the player collides with an obstacle.
Please note that this implementation is a minimal example and can be expanded upon with additional features, graphics, and improvements based on your specific requirements.