Plot: The GNOME Games collection is a collection of about 15 puzzle video games that is part of the standard free and open-source GNOME desktop environment. They have the look and feel of the GNOME desktop, but can be used without it. Wikipedia
Plot: Armagetron Advanced is a multiplayer snake game in 3D based on the light cycle sequence from the film Tron. It is available for Linux, macOS, Microsoft Windows, AmigaOS 4 and OpenBSD as free and open-source software. Wikipedia
Plot: KHangMan is an educational computer game designed for young children based on the classic Hangman game. It is part of the KDE Software Compilation, specifically, in the kdeedu package. The application features four themes. In the sea theme, each incorrect guess makes a lighthouse project another piece...
Plot: gbrainy is a free and open brain teaser game for GNOME designed for use in education. It is licensed under the GNU GPL. The game was written in C# and has since been ported to the Sugar graphical environment, to Microsoft Windows. Wikipedia