I should also say that I like the concept quite a bit (wouldn't be giving you this feedback if I didn't!), and think this shows a lot of potential. I could imagine playing it on mobile, for instance.
Thanks for the feedback! Yeah, it could be nice to just be able to connect any stones to make the crystals, without having to obnoxiously connect lines with right click. To your point about Mac's and right clicks - I could also let the player choose a color before connecting stones, and draw lines that way.