Sure, here's a simple game called "Spore" implemented as a single HTML file using JavaScript, enclosed within script tags. The game assumes smartphone operation and uses pictograms.
Spore Game
To play the game, simply save the above code in a `.html` file, open the file in a browser, and the game will start automatically. Click on the displayed pictograms to increase your score within the given time limit of 30 seconds. After the time is up, an alert will show your final score.