SuperTux

SuperTux is a free and open-source two-dimensional platform video game published under the GNU General Public License (GPL). 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.

Gameplay in SuperTux is similar to Super Mario Bros.. Tux can jump under bonus blocks marked with question marks to gain coins or retrieve power-ups such as the egg, which makes Tux bigger and allows him to take an extra hit before dying. Other objects such as trampolines and invincibility granting stars can also be obtained from these blocks. Tux can defeat some bad guys by jumping on them, and most can be defeated or frozen by shooting bullets after collecting a fire flower or an ice flower. Earth flowers grant Tux a miner helmet with a spotlight for dark areas and can give invincibility for a few seconds, and air flowers allow Tux to glide in the air, jump higher and move faster. If Tux gets hit after he collected a flower, he loses his helmet and transforms back into big Tux. The objective of each level is to get to the end, usually marked by checker-patterned poles.