Sure! Here's a simple implementation of the game you described using JavaScript and HTML. Save the code as a HTML file and open it with a web browser on your smartphone to play the game:
In this game, you control a blue player character at the bottom of the canvas using left and right arrow keys. The objective is to avoid the red enemy character that moves downwards from the top of the canvas. If the enemy character collides with the player character, the game ends and asks for a reset. You can choose "Yes" to reset the game or "No" to exit.
Please note that this is a basic implementation to demonstrate the concept. You can enhance and customize the game further based on your requirements and preferences.