Even if you can't afford it, telling everyone about it will be a HUGE help! Especially youtubers :)
The audience of the youtubers mostly decide whether or not they play.
Take mattshea (his genres of gaming are kinda sporadic though) and blitz (partially limited by income) for example
If you got someone famous (like pewdiepie or jacksepticeye, highly unlikely if they ask for sponsership and i'm betting that this happens to them often) Autonauts would experience more of a sugar rush in popularity (fast rise fast fall) but their play styles will either make or break the game.
Someone like Ssundee (a little more open-minded to games that don't include minecraft as opposed to captainsparklez; however he has taken a break from youtube) could work for a gradual incline in popularity however as I said before, if their viewers get bored of it, they'll stop too.
On the other hand if you partner-up with a well-known gaming company they would have better resources for promotion but I'm not sure whether that would go against your ethics and autonauts a game where players need deeper immersion than just an ad. You will also need players who can grasp where the game can go rather than what it is.
Some drawbacks include it lacking the near-infinite possibilities in games like Minecraft and backstory+ incentives the Binding of Isaac: Wrath of the Lamb (achievements, variety, ect) . While yes they have had more years and money for development (and the support of youtubers) people won't play Autonauts if they don't feel anything for it. You need to make them experience a sense of wonder and curiosity of what they could do in or with the game, some more substance during or after we finish automation (what if bots could educate the folks? What if they started an uprising, maybe like the dangers of artificial intelligence and thats why they've travelled to this planet rather than just helping random civilisations, that never starve and probably haven't moved since they'be been "created", along their way which would help justify why they need to start from scratch and the need research technologies. just a sense of realism).
Thats for the latest version anyway and yes you're probably a small team but think about it, what if you could automate script-writing?