Here's my confession: I've put over 100 hours into Oxygen Not Included, and I _still_ haven't beat the game. I don't think I'm even close. But I keep playing, and I keep enjoying it, and I think that warrants writing a review.

![Screenshot of my Oxygen Not Included colony](https://i.imgur.com/WakUYPl.png)
(OC Screenshot)

The above is what I've spent over 100 hours of my life working on. Or at least, the small portion of it I could fit on my screen for a screenshot. And I guess I should admit that not all 100 hours were spent on this; a good 40 of them were spent on trial and error, figuring out how to get to this point.

The game is [Oxygen Not Included,](https://store.steampowered.com/app/457140/Oxygen_Not_Included/) and the trial and error and figuring out how to do things is actually what makes this game so much fun.

Oxygen Not Included, which I'm going to abbreviate as ONI, falls into the "colony survival" genre, along with some other recent games like [Surviving Mars](https://www.paradoxplaza.com/surviving-mars/SUSM01GSK-MASTER.html) and [Rimworld](https://rimworldgame.com/). As an avid player of RPGs and RTSes, it's not a genre I saw myself getting quite so addicted to. But I had heard some good things about the Early Access version of ONI, so when it hit mainstream release (and was on sale), I made an impulsive decision to pick it up.

Well, it was sure worth my $20. It's been putting as much mileage on my RTX 2060 as any mining I've been doing.

![Promo Image for Oxygen Not Included](https://i.imgur.com/plJUqB9.jpg)
[Source](https://store.steampowered.com/app/457140/Oxygen_Not_Included/)

ONI is made by Klei, the company behind the Don't Starve games (as you may have guessed from the artwork). The premise is that you've crash-landed on a resource-rich asteroid with a crew of three "duplicants". Your crew members are called duplicants because--for reasons not made very clear within the game--you can 3d-print more of them as the game progresses.

The goal of the game is to start off with your initial duplicants and plans for building various machines and support objects, and to build up a colony with enough resources and technology to escape the asteroid you've found yourself marooned upon.

Of course, you, the player, can't build anything directly in this game; you have to ask your duplicants to do it for you. They'll generally do what you tell them to, based on priorities you give them...unless they're hungry, or upset, or sleepy, or bored.

![A bored duplicant](https://i.imgur.com/VEOATON.jpg)
[Source](https://store.steampowered.com/app/457140/Oxygen_Not_Included/)

It may sound like there's a lot to manage in ONI, and it's true. There is. Not only do you have to keep your duplicants happy and well-fed, but you have to manage their workload as they gather resources, build up your colony, operate machinery, resource new technology, and, ultimately, build the rocket that's going to get you off the asteroid. _(Or is it?)_

What makes that fun--aside from a lot of whimsical artwork and unexpected game mechanics--is the room that ONI gives you to be creative. There's a _lot_ that you can do in ONI's world, and it's up to you (perhaps with some help from the Internet) to figure out exactly what that is.

The thing is, the machines and other objects that ONI provides you with the plans to build are only going to get you so far. You can't win the game just by gathering resources, building the machines you're given, and rocketing your way to safety.

![Water purification plant](https://i.imgur.com/ph43GNi.jpg)
[Source](https://www.reddit.com/r/Oxygennotincluded/comments/a2rfsp/liquid_resevior_chlorine_water_decontamination/)

Though it may not be obvious when you first start playing, ONI provides you with an extremely comprehensive physics model. In order to succeed, you're going to have to come up with creative ways to use combinations of things you can build, along with the physics model, to do things that single machines can't do by themselves.

**This is where things get fun.**

The picture above is a screenshot that a clever Redditor took of his design for a water purification plant. This design takes advantage of the fact that, in ONI, chlorine kills germs, water can be stored in tanks, and that liquid flow through pipes can be controlled by timers.

Of course, chlorine doesn't kill germs instantly, just like in the real world. And chlorine is a gas at habitable temperatures. So this player has figured out that he can fill an airtight room with chlorine gas (the green stuff in that picture), put some liquid reservoirs in the room to hold dirty water, control the flow of water through the reservoirs with timers and valves, and--voilà--he's got a way to recycle dirty water.

That's just the tip of the iceberg. To keep your colony going long enough to escape the asteroid, you're not only going to have to clean water (since there's a limited supply), but you're also going to have to figure out how to provide electricity to your machinery, how to farm plants and animals, how to forge alloyed metals, how to keep your duplicants _really_ happy, and a lot more.

![A recreation room](https://i.imgur.com/mAE2YFl.jpg)
[Source](https://store.steampowered.com/app/457140/Oxygen_Not_Included/)

Even though Oxygen Not Included saw full release just a few months ago, it's been available as an Early Access game on Steam (the _other_ Steam!) since 2017, and that's allowed it to build up a large community. There's a [forum](https://forums.kleientertainment.com/forums/forum/118-oxygen-not-included/), a [subreddit](https://www.reddit.com/r/Oxygennotincluded/), a [wiki](https://oxygennotincluded.gamepedia.com/Oxygen_Not_Included_Wiki), and [a lot of YouTube channels,](https://www.youtube.com/results?search_query=oxygen+not+included) all dedicated to discussing new creations and ways people have figured out to accomplish goals, to onboarding new players, and just to sharing the joy that this game has been bringing people.

Seriously, you wouldn't believe how many ONI bookmarks I have in my browser at this point.

And that may be ONI's downside, in an odd way. It is _not_ easy to figure out what you're doing in this game alone. The game includes copious descriptions of pretty much everything you can click on, but what it doesn't provide is any clue about how everything works together. I had been playing ONI for quite a while before I decided to check out some videos about the game, whereupon I came to the realization that _I had no idea what I was doing_.

If you like fiddling with things and figuring out how things work, and don't mind doing a bit of research, though, this is the game for you. And if you like emergent gameplay...well, then this is _really_ the game for you. Just be kind to yourself, and check out some Internet resources _before_ you put 40 hours into the game.

[Oxygen Not Included](https://store.steampowered.com/app/457140/Oxygen_Not_Included/) is available on Steam for Windows, Mac, and Linux/SteamOS. Its standard price in USD is $24.99, and like most Steam games, it's on sale pretty often.