This is a package that serves to help get Screeps objects off of the global namespace. They're really still there, but by using this module, you'll be able to pretend like they aren't.
Where is Game?
Game is an object literal, with the way that require caching works in Screeps, there isn't a way to export it while still having it update each tick. This is one global that you'll still have to allow in your code.
You missed XXX
Yea, this is a really early phase in the module, expect breaking changes, missing globals and the like.