So I see that unity has the support for c#, JS and Boo.
I could learn one of these but I would like to make a 'compiler' or something similar that would let me write ruby code and either output JS code or make a layer that could be read by the Unity compiler.
Is this even a possibility. Im willing to invest many hours in this and have a fair bit of experience.
If your question is actually "how do I compile Ruby to JavaScript" then that's easier to answer:
Opal: Ruby to JavaScript compiler
However, you're going to be mucher better off learning one of the supported languages. It's very hard to debug "your" code when what's running is a paraphrasing of the code in another language.