Note that this contest did not require sources to be released, only 19 entries had theirs released at time of writing.
Cannonball Z is a game where you shoot zombies with cannonballs. It features randomly generated maps.The source code is in the .zip file. The engine uses a BSD license. My code is GPL and my assets are CC BY-SA.
OxyFPS is a simple first person shooter with the restriction of being in an oxygen-lacking environment.You are on an airless planet with only a suit, a crossbow and a tank of air.Your objective is to survive as long as you can while the corporate goons that caused this terraforming catastrophe hunt you down.
By the way: I participated in a project with my beginner Blender abilities but only the art assets are freely licensed.