Sure! Here's an example of an eco-friendly game implemented as a single HTML file using JavaScript and enclosed in script tags:
Score: 0
In this game, there are three buttons represented by pictograms: a tree, recycling symbol, and a solar panel. Each time a button is clicked on a smartphone, a certain score is added. The score is displayed in the top left corner of the screen. The objective of the game is to click on the buttons and increase the score, promoting eco-friendly actions like watering trees, recycling, and installing solar panels.