Sure, here's an example of a simple block breaker game implemented as a single HTML file using JavaScript and enclosed in script tags. Please note that for a better user experience, you might need to add more styling, sound effects, and improve the gameplay mechanics.
This is a basic implementation of a block breaker game where a paddle is controlled by the player and can be moved horizontally using the right and left arrow keys. You can further expand the code by adding ball movement, collision detection, and scoring mechanisms to turn it into a complete game.