Sure, I can create a simple game based on the theme of "BACKROOMS". Here's an example of how the code could look within a single HTML file:
In this game, the player starts off in room 0 and can click the "Move" button to progress to the next room until they reach the final room. Each room is represented by a pictogram, as indicated by the pictograms in the `rooms` array.
When the player reaches the final room, a victory message is displayed, and the "Move" button is disabled.
Please note that this is a very simple implementation and can be expanded upon to add more features, levels, or mechanics based on the "BACKROOMS" theme.