Sure, I can help you create a simple game using JavaScript within a single HTML file. Below is an example of a game called "Pictogram Guessing" that can be played on a smartphone:
In this game, you will be presented with a randomly selected pictogram representing a word. You need to type your guess into an input prompt, and if your guess matches the word, a congratulatory message will be displayed. Otherwise, an alert will indicate that the guess is incorrect and reveal the correct answer.
Please note that this is a very simple example, and you can enhance the game by adding more words or implementing additional features.