Sure, I can provide you with a simple 3D zombie game implemented as a single HTML file using JavaScript. Please find the code below:
This code sets up a simple game where you control a green player using the left and right arrow keys to avoid a red zombie moving towards you from the right side. If the player collides with the zombie, the game ends and a "Game Over!" alert is shown.
Please note that this is a basic example, and you can further enhance the game by adding more features such as scoring, levels, additional zombies, etc.