The developers say that Out Of Space is completely playable solo, but this is misleading. Technically it’s totally true – I have beaten the largest map solo, so clearly this is doable. However, it’s much, much harder than the multiplayer. Playing Out Of Space solo means you jump right into a special challenge mode, resulting in a difficulty wall that’s hard to get past. This makes sense with the game’s basic theme of being about the difficulties of moving into and maintaining a home with other people. The multiplayer is the game’s default mode, about arguing over who’s going to do the dishes and trying to work out a division of responsibilities that prevents you from being overrun by alien goo monsters, while the solo mode is a special challenge where you have to take care of everything yourself.
But if, like me, you have no friends (or, more likely, you have no friends who’ve bought this obscure indie game), you may wish to play Out Of Space solo from start to finish. And if you’ve tried it, you’ve probably made decent progress on the smallest six-room map, but the alien goo gets more aggressive over time, so you’ve found the tide turned against you and eventually you get overwhelmed. Worse, while the alien aggression ticks up on a timer, it also ticks up if you clear a certain number of rooms, whichever occurs first, so you can’t beat the game by speedrunning the rooms before the goo gets too aggressive to handle. You have to contain it just like you were in multiplayer, but with the resources of just one person. How is this possible?
Step 1) Shrink your front line. Once we realize we’re on the clock, we solo players tend to react by moving blindly forward as quickly as possible, trying to beat the aliens before they get too powerful. This is both impossible, since alien aggression will increase in response to the number of rooms you’ve already cleared even if you’re way ahead of the timer, and also tends to lead to salients that are impossible to defend. If you always clear whichever room is closest to the water faucet you start with, you will end up expanding in every direction and hit that critical endgame of hyper-aggressive aliens with active rooms at three different farflung ends of your space house, and you’ll have absolutely no hope of holding them all even on the small maps. Instead, when you’re expanding, take a moment to check how many doors the room you’ll be expanding into has. Doors adjacent to dirty rooms get dirty themselves, and that dirt spawns alien eggs, which spawn aliens, which spawn dirt into your clean rooms. You’re probably familiar with the general process, but note that the key chokehold here is doors: Aliens can’t open doors, which means doors are impervious as long as you can keep them clean, which means your total vulnerability is a product of the number of doors and the furthest distance between any two of them. You want to both decrease the number of doors you need to monitor and make sure that all doors are as close together as possible.
A critical part of shrinking your front line is buying and placing rugs underneath those vents that spew goo periodically. Rugs are (close enough to) impervious to getting dirty, so having a rug under a vent will prevent that vent from starting up a goo alien flanking attack which might otherwise spell your doom. No room with a vent is secure until you’ve put a rug down under the vent. You’ll still want to clean the vent off while clearing the room to buy you enough time to get the rug down, and you’ll want to make sure the floor is totally clean before putting the rug down, because dirt underneath the rug stays there and will eventually spread out from underneath it and create more alien eggs, but if you put a rug down on a clear floor below a clean vent, that vent will be unable to dirty the floor again even after it starts spewing goo again. Be warned that objects in the room can still get dirty by the goo-spew, and while this won’t reopen the front line (alien eggs can only grow on doors and walls, never on objects), it will render those objects non-functional. Despite the game’s name, you are pretty much never out of space to put down new objects even on a small map (although individual rooms can get very cramped), so it’s usually best to just leave a vent room empty.
If a battery socket is directly under the vent, this will in some ways be helpful, as the battery getting knocked out by the goo will let you know that the vent needs cleaning. The battery is not destroyed by vent goo the way it is by aliens, so you can just grab a bucket, toss the water from the bucket across the battery socket and vent (you can get both with one bucket if you angle it right), and plug the battery back in. So long as you have a rug underneath, no further effort will be required.
Step 2) Build an industrial base to feed the front lines. You’ll want to buy a number of items to serve your war on dirt, and you probably can’t get all the money you need from that purely from recycling trash bags and stunned aliens. You can set up a dedicated pumpkin farming room with outlet extenders and 3-4 pumpkin gardens, but you’ll have to constantly be re-watering the pumpkins, so this is more of a multiplayer strategy where one player can dedicate themselves purely to growing food and making money from the excess while one or more other players worry about holding back the goo and pushing the frontlines. No, as a solo player you need an exercise bike and as many house plants as possible. The exercise bike is fairly cheap, so you should buy it early on. Definitely drop any house plants you come across into the same room as the bike, as their regenerative effect will allow you to bike for longer before you need to take a break to sleep in an armchair, couch, or bed. With enough house plants (I think the threshold is 4) you will regenerate stamina faster than the bike drains it and can make money continuously. Unless you have that many house plants in the room, you’ll want to make sure a sleeping spot (ideally a bed, but a couch or armchair are nearly as good) is in a nearby room. If you don’t have enough house plants to fill up your biking room, or if the biking room is so enormous that you still have room left over even with an exercise bike, the battery socket, and enough house plants to totally cancel out bike fatigue, you can put the bed in the same room as the bike.
Ideally, by the time alien aggression has increased to the point that they’re growing eggs on doors, you will have the front line limited to just one door (although two or three is also manageable as long as they’re nearby one another), and you can then focus on setting up a bike room nearby so that you can build up as much money as you need for your future assault against the more powerful aliens. Hopefully your bike room is close enough to at least one of the doors on the front line that you can see when it gets dirty from the bike and hop off to go wash off all the doors (if one of them is dirty, the others probably are too), but you might just have to remember to check periodically.
Step 3) Move your forward operating base as you go. If you hold down the circle button (B on the XBox controller, not sure what the keyboard equivalent is but the options menu can probably help you out there), you can deconstruct any object back into a box. This doesn’t have any immediate visual effect, so don’t worry if the recycler you’re facing looks exactly the same when you first press the button. After a second or two, it’ll start to go transluscent, and a second or two after that, it’ll be a box again, and you can pick it up and deploy it somewhere else. Your forward operating base should ideally consist of a sink with two buckets, so that you can swap them out without waiting for them to refill, a recycler or mixer to dump alien corpses into, a roomba to automatically clean the floor of the new room once you open the door, your mop or broom or whatever that thing that cleans floors and stuns (most) aliens is, and an extra battery to restore power to the next room.
If you’ve turned to this guide in frustration after just two or three attempts at a solo game, you may be asking yourself “how do I get a sink or a roomba?!” You can sometimes find them for free in rooms, but to get them reliably you will need to complete achievements to unlock them in the store. A roomba requires you to recycle a total 150 objects across any number of games, but don’t worry, it’s the least important part of your FOB and you can go without it until you unlock it through normal play – grinding is not necessary. A sink requires you to beat the small apartment, but you can use a shower to replace it beforehand and may be able to beat the small map purely using the faucet at the start, which has the same function as a sink but is immovable. Showers take longer to fill a bucket, but if you’ve got a second bucket and are swapping them out, it probably doesn’t matter, since the second bucket will be filled by the time you’ve finished tossing the water from the first one onto whatever is you need cleaned.
Once you have your bike room set up, you should easily be able to maintain a front line against the alien goo until it reaches hyper-aggressive endgame mode, something I’ve never seen happen until 5/6s of the rooms are cleaned (I don’t know if it’s even possible to enter this level of aggression from running out of time, but if it’s possible, it must take at least 45 minutes). Build up enough money to get a fully operational FOB in the room adjacent to the next room you’ll be opening. Don’t give up on managing your front line size just because you’ve got a fully operational FOB, as you’ll still need to keep doors clean while you bike up enough money to buy new batteries in between assaults, so you need there to be a small number of doors (ideally one) close enough by one another that you can patrol them all quickly.
Once you’re ready to make an attack, make sure your dog is fully fed so they don’t drink your bucket water, that both your buckets are full of water, and that you are fully rested and not too hungry (you can take care of your and your dog’s hunger by buying a pizza, which shouldn’t be too hard with a fully operational bike room). Then open the door and prioritize stunning and recycling all aliens. Expect to be pushed back into your FOB pretty quickly as the aliens run past you to try and destroy your furniture, and focus on making sure they don’t escape deep into the clean parts of your house and open up new fronts. Stun all of them before they get too far, then recycle/mix them, then clean up their dirt trails and wash off any furniture they’ve managed to get dirty (though obviously you’ll have to wash off the recycler/mixer earlier in this process if they managed to get to that). Your dog will be invaluable to this process, helping take out the flying aliens or the armored aliens or other aliens that are annoying to deal with yourself but go down automatically to a dog bark.
Once the aliens are all dead, clean up the goo trails they’ve left in your FOB and then clean the floor in the new room to prevent new eggs from spawning. Your first bucket should go on the battery socket so you can power the room up, keeping the door open and making it faster to run buckets in and out as you clean off the doors and destroy any eggs before they hatch into aliens. Once you have the room cleared, pick a new target and, if necessary, move your FOB up to be adjacent to it.
Step 4) Be ready for the final assault. The rate of alien aggression really skyrockets once you have 5/6s of the house cleared. This means that the last room on small and medium maps and the last two rooms on large maps will be difficult to manage. Prepare for this by buying extra batteries and leaving them in your FOB before you trigger the hyper-aggression. This means that on small maps, once you have four rooms cleared, you should get two spare batteries in your FOB so that you can clear room six immediately after clearing room five, without having to stop and bike up money for another battery. In medium maps, you should have get two spare batteries once you have seven rooms cleared so you can do room eight and nine one right after the other, and on large maps, you want three spare batteries after getting to room nine, that way you can do room ten, eleven, and twelve all fairly quickly. The hyper-aggressive aliens are no harder to defeat and don’t move faster, but they form eggs on dirty doors and floors much more quickly. On small and medium maps, this is no problem as long as you’re prepared – no sooner has alien aggression increased then you are already assaulting their final stronghold, cleaning off their last doors and floors before their increased spwaning rate can become a problem. On large maps, you may have to race from the freshly-cleaned room eleven to contain an alien push from room twelve, so be extra-certain that these last two rooms aren’t far away from each other or you might be overrun at the last second.
Other Tricks: A watering bot will wash off dirty furniture and appliances, water pumpkin gardens, toss water on you to wake you up if you fall asleep on the floor, and fill up any empty buckets it finds, but it will not wash doors off, so it will not help you hold back the alien menace directly. You might actually find the watering bot has pilfered a bucket you were counting on to hold the tide back at the worst possible moment if you don’t have very many of them. If you want to leave a water bot to its own devices, have four or five buckets (you unlock it by buying five buckets in one match, which you can do pretty easily by biking up a huge pile of cash while you have the aliens choked at a single door), otherwise you can lock them in a room with a vent with a sink (or shower) and a single bucket, and they’ll clean the vent automatically as soon as it gets dirty, so you’ll never have to worry about it spewing goo again. This is way more expensive than a rug, but it can be particularly helpful when the room’s battery socket is directly under the vent, as the water bot will prevent the battery from getting knocked out by vent goo.
I never unlocked the chef bot. According to the wiki, it cooks food in a macrowave automatically if you have one, and will bring food automatically to you if your hunger bar is getting high. This is convenient, but if you have a good bike setup you can probably buy as much pizza as you need. Just make sure you always have a pumpkin garden or two lying around to produce emergency food if you’re so hungry that biking up $15 for a pizza would kill you. The chef bot is probably more useful in multiplayer, when many tenants means more strain on food production. Similarly, a macrowave is probably really helpful for turning one stunned alien into a cooked chicken, which four players can share for a good hunger decrease each, but for a single player, pumpkins and pizza are good enough at keeping hunger under control that the macrowave is mostly overkill. Useful if you want to avoid buying pizza for some reason (maybe you want to try and win without buying anything from the shop except batteries, or you’re roleplaying a health nut or something), since the leap from pumpkin to salad is a big difference.
A table is potentially useful to a large house’s FOB, since you can put up to three (four if it’s a kitchen table) stunned aliens on it and they’ll never revive. Putting things on the table is faster than recycling or mixing them, so this lets you clear room eleven faster, which helps you get to room twelve before the hyper-aggressive aliens can grow eggs on their doors and invade clean parts of the house. I didn’t end up using one and I didn’t miss it, though.
Televisions are useful if you find them lying around, go ahead and install them in a room and check up on them when you’ve finished a bike session. The discount they provide is huge, so if something you need happens to come up while you’re still building up your bike room/FOB, it can save you a lot of time. The goal of the bike room is to be able to build up funds indefinitely and be overprepared for your mid- and end-game assaults, though, so buying a television is probably not worth it.