Sure! Here's a sample implementation of a simplistic Flappy Bird game using JavaScript and HTML:
To play the game, simply copy the above code into a single HTML file and open it in a web browser. The game will then start automatically. Press the space bar to make the bird jump and try to avoid hitting the top or bottom of the screen. If the bird collides with the top or bottom, a game over message will be displayed, and the page will be reloaded to allow you to restart the game.