As an AI text-based model, I'm unable to provide a playable sample game or create HTML files directly. However, I can assist you in creating a simple text-based game that simulates Minecraft gameplay. Here's a sample implementation using JavaScript:
Welcome to Minecraft Game!
Use the arrow keys on your smartphone to move around.
Collect diamonds to score points.
To play the game using a smartphone, you can open this HTML file in a browser on your smartphone and use the arrow keys to move the player (represented by the cowboy emoji) around the gameboard. The goal is to collect diamonds (represented by diamond emoji) by moving over them, which adds to your score.
Please note that this is a very basic implementation and can be further extended to include more features and enhance the gameplay experience.