Sure! Here's an example of a simple Flappy Bird game implemented as a single HTML file using JavaScript:
You can copy the above code into an HTML file (e.g., `flappy_bird.html`) and open it in a web browser to play the game. The game can be played by clicking anywhere on the screen to make the bird jump and avoid the pipes. The score is displayed at the top left corner of the canvas, and if the bird collides with a pipe or hits the ground, the game ends and a "Game Over" message is displayed.