This is really cute and well designed -- both the website and CLI tool!! Some feedback:

* I might be worried about businesses using this as an actual metric of developer productivity, rather than as just a fun game.

* the readme.md in the linux tarball is pretty useless, since it just contains instructions for building the CLI from source.

* the first time setup flow (where you run ./karma and the site knows it instantly) is slick as hell, I'm blown away!

* I can't use arrow keys to navigate or edit in the "any comment?" prompt, but I guess it's supposed to be short anyway!