The new Unreal Tournament can be downloaded and played, it’s in alpha stage of development.
“You’re a Wizard, you can’t do magic, but you can jump pretty good!” WizardWizard is a platformer with skill testing puzzles and is all complimented by beats by _TWC! 25 levels to play. For windows and mac.
OpenRelativity is an open-source toolkit to simulate effects of special relativity by varying the speed of light. Developed by the MIT Game Lab, it contains open-source code for public use with the free and paid versions of the Unity engine. The toolkit was developed during the creation of the game A Slower Speed of Light.
Pythetron is an old school 2d shoot’em up (or shmup) built on a modern game engine utilizing advanced physics and 3d environments, with detailed models, animation, and sound. Pythetron takes a new direction in gameplay by allowing the game’s pacing to be controlled by the player and allowing the player to explore the galaxy in a non-linear manner by earning stars and unlocking new worlds.