Sure! Here's a simple tower defense game implemented in a single HTML file using JavaScript and enclosed in script tags. The game is designed to be played on a smartphone and uses pictograms for better visualization.
Tower Defense Game
In this game, enemies will continuously spawn on the screen and move horizontally. You can tap on an enemy to kill it and earn points. Every few seconds, the enemies will mutate and change color randomly. The goal is to kill as many enemies as possible before they reach the end of the screen.
To play the game, simply save the above code in a single HTML file and open it in a web browser on your smartphone. You can tap on the gray area to build towers (currently, it only displays an alert). Enemies will appear as red boxes and you can tap on them to eliminate them. Earn as many points as possible before the enemies overwhelm you!