Liberated Pixel Cup
The Liberated Pixel Cup was a free software game contest consisting of two phases which ran in June and July 2012. In the art phase, submissions were judged on fitting in with a supplied set of assets in a well described art style, as well as on overall quality. Afterwards a seperate code phase was held, in which contestants had to make a game using the assets from the previous phase as well as they could.
This competition was organised by the Free Software Foundation, Creative Commons and Open Game Art, later joined by the Mozilla foundation who wanted to specifically promote web games. Before the contest proper, art was commisioned in a "distinct Victorian style" suitable for fantasy and cyberpunk genres. A donation drive was held to fund prize money and further base art.
One of the goals of the Liberated Pixel Cup was to provide a body of free games with especially the art in a consistent, reusable style. Rigorous license requirements were demanded: the art entries had to be available under both the CC-BY-SA 3.0 license and the GNU GPL 3.0, whereas submitted code was required to be released under the GNU GPL 3.0.
The winners of the art phase were announced on 2012-09-28, those of the code phase on 2013-02-17. Reasons given for the long judging period, aside from personal issues on the part of the judges were: some organisational issues, the unexpectedly great quantity and quality of the submissions and difficulties in getting the games built. Aside from the judging issues, organisers seem to be happy with how the Liberated Pixel Cup turned out. If it's not sure whether there will be any more LPCs, that doesn't seem to be for lack of enthousiasm or ideas for improvement.