A continuation of the previous article, which was an overview of the concept. In this post, I'll go into some other thoughts I've had on the design. All things considered, this would be a lot of fun to develop and to play, and I hope I get a chance to later on.
First, I am not sure I explicitly mentioned, but some persistence of the map is almost obligatory, although that's a departure from both SS13 and roguelikes in general. It's obligatory because a good deal of the mechanic of the game will be construction of a sanctuary and what that enables you to do to further the story. It is a bit like Terraria in that sense; your job is to improve your lot in life until you can take on the greatest challenges on the map.
In my mind, I envision the map divided into meta- and micro-level maps, or what I will call sectors and blocks. A sector contains, let's say, nine blocks, looping on each axis; you can move from one block to the next by jumping out into space and drifting (if you have a spacesuit and are adventurous) but you cannot travel between sectors like that. While a sector is active (has any player character in it--I make no assumption that it is a single player game), random events may happen on any of the nine blocks, and you will be notified of it to various degrees. The sector's events will vary in intensity, but largely, some sectors are "safe" and some are "dangerous" in various ways, usually because they are close to some nastier sector full of space carp, traitors, wizards, cultists, clowns, or other unmentionables.
I imagine the metamap is of a mixed asteroid and debris field in orbit around a hostile planet. The debris is shattered starships and space stations; the asteroids are rocky but can easily contain a variety of useful metals. Each block may contain a ship/station, an asteroid/field, empty space, a danger map (enemies, etc--rare!), or more than one of the above--a crashed ship on an asteroid crawling with enemies, for example. Each sector must have at least one spot for a shuttle pod to land, when eventually either the player finds a tool to call one, or a random event makes one crash land. These shuttles allow either one-way, or (later) reliable transportation from one sector to the next. However, the metamap is largely unlabelled; instead, if you want to make a landing site permanent, you will want a radio beacon so that shuttles can hone in on it.
Since this is a roguelike, I am fully expecting characters to die and stay dead; this merges with the persistent map because each sector can persist. When your rogue dies, and assuming you don't have a way to clone him to the base, you start as a new rogue in the same metamap, but a random sector. When you finally get access to a shuttle, you either have a beacon pointing the way to your outpost (if you have one), or you have to take a guess and hope you found it. No matter what sector you land in, there will eventually be a way to get out, but it may be easier or harder depending on the circumstances. If you fail to find your base, or just don't have one, you have to struggle to find tools and make a new base in this crazy drifting space-world.
Base constructing, I would imagine, would feel very familiar to an SS13 player (if you haven't played, feel free to find a server and jump on--the game is free), although I imagine it would be slowed down a fair bit. The stickiest bit in construction will be finding a steady source of oxygen; once you have a basic atmosphere, plants in Hydroponics can filter CO2 for you until you find more advanced filtration methods, but plants can't produce oxygen out of hard vacuum. I expect that wreckage maps will have spare canisters lying around, if you care to wrestle them back home, but the other obvious source is chemistry; get the right few chemicals into a chemical reactor with some rusty rocks, filter out any bad particulates or gasses, and you turn rust back into oxygen and iron, or some silly conceit like that. I imagine that that would be a good early-game way to produce large volumes of gas, as long as you find the right raw materials.
Once you have a base, I expect that characters can "retire" there, and stop adventuring in exchange for giving bonuses to the station. For example, you can retire and become an engineer, which means that when the base is hit with asteroid debris, the holes will be automatically fixed. You can also retire and become a scientist, and slowly reverse-engineer tools and weapons into blueprints which can be printed on your autolathes--or improve existing designs. But you had better have a food source--someone should take up botany once you have a hydroponics bay set up--or else you had better scavenge a whole bunch of stuff to keep them alive. And you'll need some kind of engine to provide power, and atmosphere, and...
Of course, in a pinch, retired characters can be reactivated and go adventuring again, if for example something destroys your beacon and new characters can't find the place. And I expect that higher-level characters have higher bonuses to their chosen profession, which means that the longer you survive out there in orbit, the more value you are when you come home. Further, you will want all--or at least plenty--of your retired characters to be pretty good at combat, just in case something evil comes their way. I would also be happy as a clam to include cyborgs as they exist in SS13--a brain inside a cyborg shell--as a way to reincarnate your dead heroes. Granted it doesn't make a lot of sense for brains to survive in space, but I suppose it would be entirely in keeping with the tone of the game that you can make a quick chemical drink for your heroes that preserves the brain in case of death, even if you don't come back to retrieve it for months. Then these cyborgs, free of their fleshy prison, can be either adventurers in their own right, or quality and "entirely voluntary" servants of the station.
If phase I of this game is exploring and building, of course, phase II has to be tackling baddies. You will find circuit boards and other parts to manufacture sensors and comm nodes while exploring, and those allow you to make complicated electronics that you could never build from scratch. Once you have those, you will be able to keep track of the progress of evil entities in your orbital neighborhood; I imagine the enemy factions slowly expand across the metamap, first endangering sectors, then infecting them, and then spreading to their neighbors. The longer you build your base, the more entrenched the enemy becomes; you will eventually want to penetrate their encroachment and, eventually, target their main bases, ridding your orbit of their menace completely.
However, each faction has multiple bases in orbit, and when you take out one, the faction only grows stronger. If you take out a Space Wizard base, the others in the metamap will receive a buff, which both impacts your attempts to destroy them, and affects their relationship with other baddies in orbit. When only one Space Wizard main base remains, it will be hardest for you to take--but at the same time, the loot you will get there will be far superior to those in earlier bases. Syndicate, alien, and cultist bases will have a similar dynamic (Although arguably, any faction that is wild such as blobs and space carp will not, instead they simply spawn new bases a while after their base is killed).
In my head at least, enemy factions war over sectors on the metamap while you work elsewhere. Each sectors is assigned a threat ranking for each adjacent faction, and factions randomly act on sectors under their influence. When the player is there, this action triggers in-game events; otherwise, all factions in competition for the square compete, all being slightly weakened, and the winner gets some strength back depending on the resources in the sector. How hard they try depends on their own strength; if you are weakening a faction, it will lose against its neighbors, but if you strengthen that faction (for example by defeating another of their bases), it will start to win against neighbors. The larger a faction's current hold, the more resources it has for these fights as well.
In reply, of course, you can eventually establish new bases of your own. This takes technology: point-defense weapons, teleporters, shuttlecraft, AI, shields, and the normal accouterments of the space station (power, food, air, etc). It will take a lot of scavenging, a lot of research, and a lot of colonists to make this dream come true, but some day, the entire orbit can be covered in your defensive network, making for a complete victory for your side.
Or not, if you prefer; you could simply make a protective bubble and sit content in your sane little corner of a crazy space battlefield forever. It's up to you...