Sure! Here's an example of a simple RPG game implemented as a single HTML file using JavaScript and enclosed within script tags:
In this RPG game, the player starts at level 1 with initial stats (attack, wisdom, and charisma) set to 1. The player can choose to fight an enemy, find a secret, or talk to an NPC.
Fighting an enemy increases the player's attack, wisdom, and charisma randomly. Finding a secret increases the player's wisdom and counts as a secret found. Talking to an NPC increases the player's charisma.
The game continues until the player chooses to quit by entering an action other than fight, find, or talk. The game displays alerts to provide feedback on the player's actions, such as level gained, stat increases, and discovered secrets.
Note: This is a basic implementation and can be expanded upon to include more features, visuals, and complexities as desired.