Pingus is a free and open-source puzzle platformer in the classic Lemmings mould — except the crowd you are trying to save is a troupe of small penguins. Each Pingu walks forward on its own, so you can only influence the herd by handing out the right command at the right moment: build a bridge across a gap, dig through the floor, block the others from walking off a cliff, or send one heroic pingu swimming ahead. Levels are solved by combining those actions in the right order, and there are several ways to finish most of them. The project was started at the end of 1998 by Ingo Ruhnke, has grown well beyond being a straight clone, and today ships 77 playable levels across hand-made and community levelsets, with original artwork, a built-in level editor and its own ideas such as the worldmap, secret levels and new actions like the jumper. It runs on Linux, Windows and macOS, and the latest stable release is 0.7.6 (December 2011) — long-lived, still installable from every major distribution, and under active maintenance upstream.
Pingus is one of the longest-running free software games still alive: nearly three decades of development, a complete single-player campaign that runs offline, and no accounts, ads or storefronts involved — install it from your distribution’s repository and play. It is genuinely good at what it does, too. The puzzle design assumes you will experiment, fail and replay, the levels are short enough for a coffee break, and because the failure state is instant and retrying is cheap, it works as well for a five-minute session as for an evening of grinding through a hard levelset. Because the level editor ships with the game and the levelset format is plain and well documented, it is also a friendly first project for anyone curious about how open-source games are built: install the game, load the editor, and you are modifying a real game the same afternoon. Development continues openly on GitHub, where the master branch has moved to a Nix-based build with Windows cross-compilation and new tooling.
Linux · Windows · macOS (SDL2-based; community ports exist for other systems)
GPL-3.0-or-later — open source; code and game data (artwork, levels and sound) ship under the same free licence.
pingus.seul.org · project site · source on GitHub
SuperTux — another long-running free 2D platformer with penguin mascots, hand-drawn levels and an included level editor.