This is a packaged snapshot of the live (as of writing) free-online web hosting of the game Sky Dragon Story from http://www.psychsoftware.org/SDS/ .

It contains ONLY the game files.

The game files need a web browser in order to run.  Specifically, they need a web browser compatible with the web standards which existed in the year 2022 (or thereabouts).  Preferably, a browser based on Google Chrome or Chromium (tl;dr: web standards have never, in fact, been all that standardized).

The live website should have some bundled Windows executables which implicitly run the game within a compatible browser.  These bundles are nearly 100MB, while the game proper is closer to 7MB (13MB with PDF manuals), hence offering this BYOBrowser zip as an alternative.

Depending on how your system is set up, you may be able to simply double-click the .html file to launch the game in your default web browser.  Alterntively, you may need to launch your web browser and then explicitly choose "Open File..." or similar from the File menu (which may require enabling standard menus in your browser settings).  Either way, performance of all features is not guaranteed if your web browser is too different from the original development browser.