The original genesis of the SSO mechanics comes from a moment in the Danny Boyle film Sunshine, which I'm about to spoiler in explaining my inspiration so stop reading if that's a concern.
In the film the ship's mathematician miscalculates a route, damaging the solar panels powering the ship. The Captain is killed making repairs, leading the mathematician into a suicidal depression. Once the crew realize that there is insufficient oxygen for the entire crew to complete the mission, a discussion arises as to whether to leave the mathematician to his own devices to effectively increase the oxygen supplies.
That moment of discussion was what the mechanics of SSO sought to recreate. As such every mission starts with roughly half the necessary oxygen needed for all players' crew to complete the mission. Players are presented with one of two general methods for success, firstly they can set about generating extra oxygen and completing sub-missions to speed up games end; secondly they can find methods to reduce the number of breathing crew belonging to their fellow players to increase their own chances of success, depending on how "semi" they take the semi-co-op to be.
I've been writing games in one form or another for most of my life but it wasn't until recently, working on games design with Mike Hutchinson on the Osprey games release Gaslands, that I realised I had the necessary skills to write and release a game to the general public.
I'd been playing around with the idea of a horror game for some time. The traditions of horror, comedy and mystery are extremely problematic for a game designer since they generally rely on surprise and set pieces, things a game with replay value struggles to do. Recently several excellent games have taken on this problem by producing essentially single usage games, in fact ever since Sherlock Holmes: Consulting Detective in 1985 that has been a valid solution. That rout was not open to me for two fairly simple reasons. Firstly, that format of game is significantly expensive to produce and not only am I unable to cover the cost and weight of design such a game would require but I'm personally unconvinced that such games achieve anything like a reliable level of payback for their investment. Secondly, I'm of the opinion that digital games, written works, movies and TV deliver those sort of set piece moments much more efficiently and effectively; I don't work in any of those formats, I work in tabletop games design and I intend to make virtues of its limitations.
As much as there is horror in the unknown, what John Carpenter described as "the 6 foot cockroach moment" (you hear a scratching at the door, you pray in terror that it not be a 6 foot cockroach. You open the door to discover a 6 foot cockroach and sigh in relief that it wasn't a 60 foot cockroach) there is a certain other horror and tension in the very exactly known. It's horrible knowing you'll die, it's horrific knowing that you'll die at 4:14PM by being crushed under a runaway steam roller. That is the form of horror I've been aiming at in this game. Now, again, knowing that your crew will all suffocate in 6 turns is frustrating and dull. Knowing that they'll all suffocate unless you achieve something difficult and complex, or something distastefully ruthless, now that's our sweet spot.
Having decided that horror was the puzzle I wanted to answer with this particular game the important question was one of setting. To be honest it wasn't a very difficult question to answer. I knew I wanted the game to be resilient to expansion which ruled out single story settings such as distant mountains or subterranean caves. That led me to one of two settings. The most obvious is the isolated mansion, the classic haunted house setup, but I didn't see much point doing what Betrayal at House on the Hill has already done as well as I could imagine doing it. The second setting of a range of classic horror and high tension films was the sci-fi, isolated space ship/station. While there have been single setting, single story sci-fi set games I genuinely don't think an attempt has been made to create a single setting, multi story sci-fi horror game. Which is odd when you think about it since it saves needing to explain why you can't just walk out or call for help and is rich with iconography and excellent horror survival stories. Just as a quick list, 2001, Alien(s), Sunshine, The Thing and Event Horizon in cinemas, System Shock and Dead Space in computer games, and a range of TV shows from X-Files and Dr Who to Star Trek. For that matter, imagine how genuinely terrifying tribbles could be if they weren't so cute.
So I had my basic task set for me, as a set of rules, setting and characters to allow for a range of stories and as much expansion as possible. As such things seemed pretty clear, a modular board, usefully generic characters and a set of mechanics that both provide interesting pressure as stand-alones but have the flexibility to describe a multitude of situations.