Sure! Here's an example of a simple tower defense game implemented as a single HTML file with JavaScript enclosed in script tags:
In this game, you can click on empty cells in the grid to place towers. The towers are represented by gray-colored cells. The grid is initially filled with empty cells. The game logic can be expanded to include enemy movement and tower defense mechanics.
Note: This is a simplified example just to demonstrate the basic functionality of placing towers. You can modify and enhance this code to suit your needs and add more features to make it a complete tower defense game.