LÖVE (also known as Love 2d) is a free 2D game engine self described as "an *awesome* framework you can use to make 2D games in Lua. It's free, open-source, and works on Windows, Mac OS X and Linux." Love is licensed under zlib and thus can be used for both free and non-free projects.
For more information on how to make a game or program with love, see the Love2d Wiki
How to Install in Fedora
Love has been reviewed and is going to be submitted for updates testing within a few days. Check back later on this page as it will be updated when as package becomes available.
The Unstable Version
For games like Mari0, you will require the unstable version. Fortunately the maintainer for Love is also planning to post unofficial builds for the unstable version for the time being. Unfortunately this is still a work in progress and may not be up for a few weeks.