Pygame is a cross-platform set of Python modules designed for writing video games.
License: Open Source
Apps available for Mac OS X Windows Linux Android iPhone
Unity is a cross-platform game engine developed by Unity Technologies. Developed by Unity Technologies
License: Free Personal
Apps available for Mac OS X Windows Linux
Pygame is a lightweight library ideal for 2D game development and is great for beginners, while Unity is a powerful game engine that supports both 2D and 3D games, but has a steeper learning curve and higher resource demands.