Another great suggestion. As a matter of fact, I am currently reworking the tutorial to be in a somewhat better shape, and I had ideas about localization for it.. but it included changing the language based on which language you had downloaded etcetera, which is a change I don't feel like I have time to implement at the moment.
However! I do believe it is high time that I soon implement a localization system. Thank you for the suggestions on how to implement it and your offer to translate the UI into Polish (That'd be awesome!). It would indeed require some rework, but nothing too painful. Hopefully I'll get onto this soon.