As an AI text-based model, I can provide you with a simple example of how you can create a game using JavaScript enclosed in script tags within a single HTML file. Since the topic you mentioned is "Oman war," let's create a simple text-based strategy game where players make choices to navigate through different scenarios.
Here's an example code that you can use as a starting point:
This is a simple game where the player is presented with three options: attacking, reinforcing positions, and gathering intel. The player's choices affect their score, and to win the game, the player needs to reach a score of 10 or more.
Please note that this is just a basic example, and you can expand upon it by adding more complex gameplay mechanics, visuals, and styling to make it a more engaging game suitable for smartphone operation.