Yes, the command "publish.coffee" is a CoffeeScript tool which publishes a given game target to the CDN. The different colorful letters represent the state of each asset as it moves through the upload pipeline, e.g. "U" for unchanged and "F" for finished.
Our engine and Project Atlas are written entirely in CoffeeScript, but that's not a requirement of game code.
Have you heard of ToffeeScript? It adds a nicer sync syntax as an alternative to nested callbacks. please take a look. I have been using it a lot but I am sort of concerned that no one knows about it so I am trying to promote it everywhere.
Our engine and Project Atlas are written entirely in CoffeeScript, but that's not a requirement of game code.