Sorry for the double post, but I felt motivated to set up the project myself and created a repository for it here:
https://github.com/tdeeb/SuperMarioBrosOnlineRevivalClone the repository, download the newest version of Unity (5.5) and ask me to add you as a collaborator if you don't have sufficient privileges to push and pull from the repository (set up a GitHub account if you don't have one). When installing Unity, only select to install the Unity editor and VS Tools for Unity, as the other things are unnecessary for us.
Right after you open the project in Unity for the first time, immediately go to Edit > Editor > Asset Serialization and set the Mode to "Force Text" if it isn't set already. Git handles Unity assets forced as text much better and will give you fewer problems with this setting.You're free to use whichever editor you prefer, but I have the .gitignore file set up for Visual Studio 2015, and Unity integrates with it extremely well. You may have to adjust the .gitignore file if you're using a different editor and don't want to track the editor files it creates. Furthermore, if you do not use Windows as your OS, you can still help with this project as Unity (and Git) is cross-platform.
If you're not familiar with Git, I suggest you read up on it here:
https://help.github.com/articles/good-resources-for-learning-git-and-github/The command line allows for more functionality but I prefer using a Git client, such as Git Extensions. Other clients people use are SourceTree and the GitHub Client, but I'm strongly opposed to the latter as it is not as well-developed as the others and doesn't provide as many features (to put it into perspective, I worked with a non-technical artist who had trouble with it despite how minimal its UI is).
Currently all the project has is a placeholder image with a script that allows for unbounded movement. I created an AudioManager for playing music and sounds but didn't test it thoroughly. Right now I'd like us to focus on client-side functionality, then hook in a server using Unity's networking, as I've heard it has greatly improved. However, feel free to work on whatever you want.
If you have any questions feel free to ask.
Update: We now have a dedicated SMBO Revival channel on our Discord server. I recommend anyone interested in participating to join it, as that will likely be where most of our discussions will be had. You can join it here:https://discord.gg/jud3Bsb