As an AI text-based model, I can provide you with a simple example of a text-based game that you can run in a single HTML file using JavaScript. However, please note that creating a high graphics game with NPC, environment, multiplayer, vehicles, animals, etc., requires advanced knowledge of game development and is beyond the scope of this response. Here's a basic example:
This is a simple example where the user is prompted to enter their name, and then they can choose to either play the game or get help. The game loop allows them to continue playing until they enter "quit". Feel free to modify and expand upon this example to create a more elaborate game.
However, creating a comprehensive high graphics game with multiplayer, vehicles, animals, etc., would require advanced game development knowledge and extensive coding. It's recommended to use game development frameworks like Unity, Unreal Engine, Phaser, or others that provide robust tools and resources for creating such games.