When was at E3 last year, its trailer ended with an arrival window flashing between "Late 2016" and "Early 2017." With no big announcements since then, I assumed Don't Starve developer Klei had pushed that window back, but it turns out it already hit it as planned. In fact, an since the middle of last month.
The doesn't show up if you search for it within Steam and still lists a release date of May 2017, but Oxygen Not Included is very much purchasable and playable right now. Klei quietly announced it was happening on on February 15, linking to the alternate Steam page from there—also adding a note to linking to the forums. Seeing as Oxygen Not Included was definitely last year, this has to be one of the most low-key launches of a great game I've ever seen.
Klei is careful to point out that alpha does mean it's not finished, but that the game is in a playable enough state that the studio wants to start gathering feedback. "We still have a lot of things planned for Oxygen Not Included, however we now feel that the game is fun and interesting enough that we want you to give it a try," the announcement post reads. It also says the game will launch in Early Access first when it does eventually get a full release, and that the current price of $20 is expected to go up.
Klei included an alpha roadmap as well, including adding more temperature related things, more ways to creates sustainable systems in your base, improved stress gameplay, new biomes, new creatures, and more. Being an alpha, Klei also specified that all of this was subject to change, and it expected to update the game "about once every 4-6 weeks" for now.
So while it's obviously not the full game, and not even the Early Access version, there's nothing stopping you from getting your hands on Oxygen Not Included right now, which I imagine will come as a surprise to most. You can find our below, along with an .