Plot: Pingus is an open-source video game programmed by German developer Ingo Ruhnke. It is a clone of Lemmings with penguins instead of lemmings. 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: Tux Racer is a 2000 open-source winter sports racing video game starring the Linux mascot, Tux the penguin. It was originally developed by Jasmin Patry as a computer graphics project in a Canadian university. Wikipedia
Plot: SuperTux is a free and open-source two-dimensional platform video game published under the GNU General Public License. The game was inspired by Nintendo's Super Mario Bros. series; instead of Mario, the hero in the game is Tux, the official mascot of the Linux kernel. Wikipedia
Plot: SuperTuxKart is a free and open-source kart racing game, distributed under the terms of the GNU General Public License, version 3. It features mascots of various open-source projects. SuperTuxKart is cross-platform, running on Linux, macOS, Windows, and Android systems. Wikipedia