Sure, here's an example of a simple roguelike game in a single HTML file using JavaScript:
Roguelike Vehicle Simulator
This HTML file sets up a basic roguelike simulator where you control a vehicle (represented by a pictogram) and need to avoid colliding with obstacles. The game is played using the arrow keys on a smartphone. The player vehicle is represented by a blue pictogram, and the obstacle is represented by a gray pictogram.
The JavaScript code adds a `keydown` event listener to the document, which calls the `movePlayer` function whenever an arrow key is pressed. The `movePlayer` function updates the position of the player vehicle based on the key pressed. It also checks for collisions between the player vehicle and the obstacle using the `checkCollision` function. If a collision occurs, an alert is displayed saying "Game Over!".
Please note that this is just a basic implementation to get you started. You can expand and modify the game according to your requirements.