I just ran a demo of it today. There are solo or GMless rules in the back, but i think it's best with a GM who has planned a few rooms ahead and come up with more fleshed out scenes/encounters for them. That said, it does provide a lot of good imagery and framework.
Thank you! That is what I came here to say. (Sorry about the delay on that Dimmendark).
Facility is best with a GM and 2-4 players, but works quite well as a 1 on 1 game.
Solo rules were added at backer request, but are not as thoroughly playtested as the core Breathless rules. If you have any suggestions or notes to add to them, please leave them here!