Sure, here's an example of a simple dodgeball game implemented as a single HTML file with JavaScript:
To try this game, simply copy and paste the above code into a new HTML file, save it with a `.html` extension, and open it with a web browser on your smartphone. You will be able to control the player using the touch controls or arrow keys and try to avoid the balls falling from the top. The score will increase for each successfully avoided ball, and the game will end when a collision occurs.