Sure! Here is a simplified version of the game you described, implemented as a single HTML file with JavaScript:
In this game, you control a tiny character represented by a white square and fight giant monsters represented by red squares. You can move the player using the arrow keys on your smartphone keyboard and attack monsters by pressing the space key. The bullets are green squares that move upwards to hit the monsters.
Please note that this is a simplified example, and you can expand upon it to add more features, additional levels, unique organ landscapes, magic attacks, and rare weapons as per your requirements.