So I have come to play and to love Factorio, a smallish game about automation, creation, and some amount of defense against alien hordes. I have to emphasize the "smallish" part; I haven't finished it, but I have a hard time envisioning the latter portions of the game as engaging me quite as much as the development challenges in the early game. As I can never really step out of my armchair game designer shoes, I wondered to myself: what would I do if I were in charge of a sequel?
1. The theme: A game about terraforming and colonization
The mechanical premise of Factorio leads itself very well to the idea of a constantly increasing scope of play. From the first few manual creations to the final gigafactory deployments, Factorio has you thinking about logistics and the future. For a large section of the game, you are making marginal gains in production and reinvesting the results in research, which for the most part is actually kind of unrewarding. I wonder if perhaps a bit of re-theming could add intermediate stages where you need to take care of ever-increasing populations of Meeples--nonhuman workers who may be, for instance, necessary for research or production, but have little or no essential interaction with the player.
Meeple management requires the addition of several resources, and their deployment throughout your infrastructure: namely, food and water, and in some cases, air. (If you really wanted to be cruel, you could ship out waste as well). With the addition of Meeples as a resource, however, you can add whole systems of research and development without complicating the game; meeple vehicles and their upgrades, meeple buildings (housing, education, healing), meeple soldiers, etc.
This does not substantially change the formula, except that it makes it in some cases more difficult to make compact settlements, which honestly is my favored way to play. And given that the existing Factorio gameplay is fun and sound, you could easily make Meeples optional--their impact on production and research can be handwaved out for "classic" gameplay. That gives you an entire set of difficulty levels: No meeples, invulnerable meeples, meeples that need food and water, meeples with advanced needs, maybe even Meeples with wants and free will--but that gets seriously complicated, not only for the player, but the programmer! Similarly, the player himself (or herself) can have some, all, or none of those basic needs, at the player's discretion when they start a game.
On the subject of "air" as a basic need, making terraforming part of the game allows you to turn air into a basic resource, whether it is generated by chemical factories, plantlife, game events (suppose the game has a non-survival gamemode--can you purchase supplies as orbital drops? Why not drop an asteroid with water and oxygen?), or other, and whether it is spread worldwide or contained in habitation domes, or contained in underground tunnels--but more on that in a moment.
In particular, combining the Meeple need for food with plantlife-terraforming allows a certain amount of feedback--but at the same time, the Meeple population grows and consumes more air. Plantlife could also feed on otherwise toxic gasses, or at least, plants could be bred to resist, filter, and convert some amount of toxins into inert biomass, which may go back to being fuel. If toxic gasses and polution are still causing alien attacks (and that's fine by me), finding ways to filter or contain those gasses may also contain the damage.
The independence of these systems is I think a critical feature; some people will by a sequel like this hoping for more of the original gameplay, while others will look for a greater challenge, and yet others are willing to explore, but piece by piece as they learn the systems. Keep the systems independent and toggle pieces on and off in game creation, and it will be an excellent sandbox to play in.
2. The Underground and Game Layers
Factorio is a game about a single plane of existence--at most you could say that the flying drones offer a pseudo-airspace that goes on above, but for the most part, everything you see is laid out before you. And that's not bad, but it could be substantially more interesting with the addition of layers, and especially the underground.
A large amount of Factorio's gameplay revolves around mining, and monsters; both of those have a place underground. With or without Meeples, mining operations can be, very simply, "Dig that way forever" or "Dig in all directions from this point"--or they can be more complex, with mineral detectors and scouting expeditions and searching caves and underground water and oil and flammable gasses and breathable gasses and poisonous gasses, and... well, the list goes on.
More than that, once you have dug out underground--or built a tower upwards, perhaps?--you can use the new space for manufacturing and logistics, or just to keep your large quantities of breathable gas that you've been generating, or to hold reservoirs of water or oil closer to home. Combined with Factorio's constant efforts to automate production and transport of goods, splitting your operation vertically instead of horizontally is an interesting addition--but again, an optional one. It seems unlikely to be strictly necessary; there for people who enjoy thinking in three dimensions, but the value added may not offset the cost for people who get a headache thinking about too many things at once.
And that's okay. I enjoy the thought of a tower of production that, like Ford's famous factory, is a black box to turn raw resources into finished goods, but there are lots of games I don't enjoy that others do, and vice versa.
Those underground passages and mining expeditions, however, are also a unique addition to Factorio, if you consider that monsters may spawn underground. Imagine as a starting point a mining train that digs three-wide foward, stores whatever it dug, and lays track into the new square so it can move up. In this resulting tunnel, if you breach a monster lair, they will destroy your train and then take the tunnel back to your camp. No matter how well you defend the tunnel, you will lose the train--unless you can also mount weapons on the train, or escort it with armed meeples, and you may need a lot of support either way. But if you fail to defend the tunnel, the attack will pierce into your underground, and then your overground, likely in the middle of your production area.
Similarly, striking water or oil underground, or a fire that catches on coal dust or oil or flammable gasses, can devastate your operation. Factorio, at some parts of the game, can be very static--which is good, since so much is built around planning and investment--and having an option for more disasters, especially preventable ones (fire or flood alarms, automatic gates) is also good. Too much? Turn it off and never think of it again. But some people feed off of having their world shaken up from time to time.
3. Cooperative and Competitive Multiplayer
There was a game series early-ish in my childhood called Outpost, with one sequel. It is about colonizing an alien world after the destruction of the earth; the last hopes of humanity are loaded in a colony ship and sent off into the stars. In the immortal words of your AI overseer, "Any mistake at this point will doom you and your colonists to certain death; have a nice day." In the original, one of your two seed ships is sent off to form a splinter colony, presumably due to some kind of internal strife; there never really is any competition because the game was not adequately finished, although given that it was a Windows 3.1 game, expecting it to be full and complete would probably be asking a bit much. The sequel, going too far in the other direction, was simply a real-time strategy game with the trappings of the original.
A game about colonizing a hostile world allows cooperation and competition both. A game with defense towers and underground tunnels and meeple soldiers (and flammable liquids and easily-broken atmospheric domes) has an inherent openness to the concept of warfare. The mechanics I've suggested lead to a number of ideas already, but here are more: allow meeples to tame monsters; allow meeples to ride monsters; air-drop meeple soldiers; air-drop monsters; orbital-drop munitions; orbital-drop monsters; allow players to import copies of their colonies to start a competitive game mid-game; allow players to send seed ships from finished colonies, with whatever supplies and technologies they please, to start a new competitive round fresh; start both players with the same advanced technologies and resources.
Cooperative multiplayer on the one hand can be the same as it is now... plus, you can have separate colonies on separate servers that trade resources via rockets with your friends on Steam, or with other saved games you have locally. If the core of the game is "colonization" instead of "survival", or it's both, then trading resources is not a terrifying prospect--but only once you get past the survival portion of your game. I imagine that getting past making rockets, and then focusing on terraforming, will require all kinds of resources to tackle all sorts of problems.
"Terraforming and colonization" is three words that summarize a plethora of ridiculous bullshit that goes into the logistics of either task, let alone both. Terraforming is atmospheric chemistry, genetic modification of plants and animals, getting and distributing tons of water, seeding the world with plants, fish, and animals, and more. Some, all, or none of this could be modeled in any way, shape, or form. Some of these tasks could be one-time or on-going puzzles.
Colonization is also a task so momentous that using only word seems unfair. Setting aside all talk of politics, shuffling meeples from one facility to the next requires either a large amount of footwork or a centralized system with its own GUI. Even just creating a new settlement using Meeples from another requires a choice: how many, and what type? For any given settlement of meeples, what is the correct population growth rate? How many meeples do you train as soldiers, or researchers, and how much investment do you put into their training--is there only one generic meeple soldier class, or are there advanced soldiers? Are there advanced researchers?
Maybe research itself has puzzles required--or optional--to its advancement. Maybe solving sudoku while you wait increases your research speed. Maybe solving a sliding block puzzle is necessary to finish a project. There are a multitude of possible minigames, each of which could be independently toggled on or off independent of each other, with corresponding changes to other constants--for example, if there are no advanced soldiers, perhaps monster difficulty scales differently. The more optional games you have, and the more ability you have to customize what goes where, the better.
Factorio is fun. I know that it is a game with a small development studio behind it, and so it's likely that nothing that I dream of would ever come to fruition. I am a little sad, but I am okay; Factorio is fun. It will wear off with time; it has begun to already. But I like it for what it is, and it inspires me to dream of even greater things that may come someday.