Members of GOG the gaming community sometimes complains that the games they buy on their platform suddenly disappear from my OWNED games list . This is a minor aberration, so there is nothing to worry about, just follow the instructions listed in this article to recover the missing items. GOG game back in GOG Galaxy on your Windows computer.
On some occasions, following the GOG GALAXY update, games may disappear from your list of installed games. However, this problem can be solved easily by simply importing the games. There is no need to download the game again. We will show you how to recover GOG game when it disappears, not showing or disappeared from GOG GALAXY.
The method may lead to additional downloads as well as overwriting of files in detected game folders. If you're ok with that, then continue.
Open GOG GALAXY and click on the Settings icon visible as a cog icon in the upper left corner of the window.
Next, from the list of options displayed, expand the Add games and friends menu by clicking on the adjacent side arrow.
Next, scroll down to the Scan folders for GOG games Entrance. Hit the Select Folder button.
Instantly, GOG Galaxy will start scanning and importing existing games. Installation from old game downloads may not be detected, but can be added manually. Simply select a game from Library and click on the Next option. Then choose the desired option.
No, there is no mandatory requirement as such. You don't need GOG Galaxy to install or play a game on GOG. It's just an optional software package to provide convenience for people who want it, but no game requires it.
All games downloaded from GOG are provided as a self-executable (exe) installer file, so you don't need any additional apps or launchers for that. Simply double click on the exe file to install the game to your hard drive. Once the installation is complete, shortcuts will be added to your start menu, desktop, and game explorer.
Hope this helps!
Read: How to fix GOG Galaxy Launcher low disk space error on Windows PC.