Hey, I'm the dev of Cosmoteer. I can confirm you are correct, I'm trying to get feedback, bug reports, and to build a community before switching to paid. In the meantime, thanks for playing!
I don't think you should wait. People seem to be having legitimate fun playing it, so you've already got one up on most early access games. I think it would be a real bummer if your game blew up and you weren't financially rewarded for it, unless you already have so much money that it doesn't matter.
Thanks to you all for encouraging me to sell it now. I honestly don't think I can do that yet given the bare-bones state of the singleplayer campaign. I think there would be a significant portion of negative reviews complaining about that.
Go greenlight. They Are Billions launched early access without a campaign and did just fine. Same for The Long Dark. Wreckfest was notorious for it's long early access cycle (years!), but turned out fine.
Why not make it Early Access (if you're actually planning on releasing a fully fleshed out singleplayer campaign), brand it as a sandbox game and be clear about what's working and what's not yet implemented?
I would buy this game based just on the info you put on the website :)
I'd buy it right now if I could. I got hooked instantly and only slept 4 hours last night as a consequence, I'm sitting at work thinking how I can fix my build. It's seriously decent enough for an early access title, all it needs is more fleshing out for the campaign and some UX improvements on the menus.