Rescue Girlies is a fork of SuperTux by a father, R. Bassett Jr., in August—December, 2013, he said:

I made RG as a Christmas gift for my children. Run, jump and think your way through the campaign to save your loved ones. Make new friends, eat some cupcakes, and squish many bad guys along the way!
https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg7Lvyhyphenhyphen8XTtvTyh24ffCCFd0rWJcraQw4EtxEx_64yF5V-B1NsBJAxC8Qc1JLSrHtsSM2JqqYRu9eefHghprmMPdvQEjY5-5X5EC3fcpWNN3Kp6PckJ-KkI88PgA4ARonKAuN-xwy7MvU/s800-Ic42/RescueGirlies.gif

Watch this video for more.

You must read the story that this father tells his daughters in the video with his own voice, really telling the story, this has to be one of the best Christmas gifts you can get when you are a kid.

Rescue Girlies was forked off SuperTux 0.3.3 (2010-08-06) by R. Bassett Jr., written in C++ with SDL under the GPLv3, currently git-bd68ac8 (2015-01-21)