If you want to play for free without a full download, you can use the official browser-based version:
Websites claiming to offer a "free download" of the full PC version are unofficial and potentially unsafe. To ensure your PC's security and support the original creators at Temple Gates Games and Rio Grande Games , it is recommended to use only the official stores linked above. Roll for the Galaxy App Now Available! - Rio Grande Games roll-for-the-galaxy-pc-game-free-download-full-version
You can buy the authorized digital version from these official platforms: If you want to play for free without