Below is an example implementation of a simplified version of the Hungry Shark game using JavaScript and enclosed within script tags in a single HTML file. This implementation assumes smartphone operation and uses pictograms where possible. Please note that this is just a basic implementation and can be expanded upon to make it a complete game.
Note: This implementation only includes the basic structure and functionality of the game. You would need to add more game logic, such as handling collisions, adding obstacles, and implementing different levels, to make it a complete and playable game.