Offline Conversion for HTML Game

My single-page HTML5 game still reaches out to Google Sheets through an Apps Script endpoint; that is the only piece keeping it online. Everything else is already bundled locally. I want the game to ship as a self-contained folder that works without any internet connection at all.

The task is to replace those Google Sheets calls with a local solution. I’d like the data that was coming from Sheets to live in a lightweight local database—IndexedDB, SQLite (via sql.js), or anything similarly portable that sits beside the game files and loads instantly when the page opens. Nothing needs to sync back to the cloud; read-only access is enough for this first pass.

Key deliverables
• Refactor the existing fetch/Apps Script logic so the game pulls the same JSON from the local database.
• Supply a script or small utility that converts the current Sheet into the local DB format so I can update content myself later.
• Produce a final build folder (HTML, CSS, JS, assets, database) that I can unzip on any computer, double-click index.html, and play offline with identical behaviour to the live version.

I’ll provide the current codebase and a sample Sheet export as soon as we start. Clear comments in the modified files and a brief “how it works” note will be enough documentation.