I uploaded the Unity 5 source code and project for the 2D Platformer being built in the Unity 5 2D Platform Game Tutorial, to GitHub.
|Unity 5 2D Platformer Demo on GitHub
Here is the link to the Unity 5 2D Platformer Demo on GitHub
Using GitHub to fork and clone a repo is easy enough.
The project steps are checked in with tags. To work with any particular tutorial version, just checkout the tag for that tutorial.
Once you’ve cloned the project, you can create a branch of the tagged version like this:
git checkout -b branchname tagname