Many many years ago when I started game development, I knew that I wanted to give back to the community. One way I decided to do that was to open source my games after a certain period of time. It was never a set amount of time, but I wanted it to be a reasonable amount of time such that the code is still useful.
So to that end, I have open sourced a whole bunch of my games. All source is available on GitHub. I am still working on notating the version of HaxeFlixel used to make the games, but the code is at least there.
All games are released under the MIT open source license. So feel free to build on them, contribute to them, or just look at them.