Pingus is a free and open source 2d side scrolling puzzle game for Linux, Windows and MacOS. In this game you need to guide large groups of penguins through various obstacles and dangers to safety. It is old classic gold Lemmings like puzzle game and heavily inspired by it. It is released under the GNU GPL license. It comes with more than 77 playable levels and you can also build your own levels using the build-in level editor.