Muut is a forum, just not in the same style of PHPBB, etc. It's free and embeds easily into SquareSpace, there's zero admin needed (like backups and patches) and there's virtually no spam. Basically, zero hassle! One other option I've thought about is just using a subreddit as a forum. Any other suggestions?
Hm. Zero administration is a plus, I didn't think of it from that perspective. That's a good point, thanks.
Subreddits don't integrate into websites though (so you'd have reddit.com/r/fungus, not fungusgames.com/forum) - as far as I know anyway. You could have a subreddit as well if you wanted I guess! I'm surprised there isn't one actually.
I guess I'd have to set it up and tbh I've already got folks getting in touch via muut, twitter, facebook, youtube, tumblr, github and gitter :)
https://www.reddit.com/r/UnityFungus Just made one, if you are interested, just contact me on reddit. I could add you as a mod and maybe even get you some guys who could help set it up.