The factory construction game "Factorio" has sold 3.5 million copies, developer Wube Software reported in its year-end update. This is an incredible validation of success for a game that would be politely described as a niche concern for mainstream gaming.

"We reached another sales milestone this Christmas, surpassing 3.5 million units. We continue to have steady and constant sales of around 500,000 every year, which in retrospect validates our initial no-sales policy that we have stuck to since launching on Steam in 2016," Wube said in a blog post (opens in new tab). The post includes an extended teaser image, several small development updates, and a summary of statistics about Wube's mod portal feature.Wube Software also announced that for both full-size rigs and mobile PCs like the Steam Deck, the game s new console controls (open in new tab) for the PC version, and announced that they are continuing work on porting the controls to the PC version.

Concurrent with this announcement, Wube Software also posted a slight teaser for the Factorio Expansion. The studio created a "Christmas postcard" that includes "a sneak peak of some new item icons." Nothing is certain in this game, which involves technologies as diverse as wood-burning steam engines, petrochemical refining, and nuclear fission, but let's guess anyway.

Although Factorio cannot handle hot liquid metal, this red icon looks like a blast furnace. Next to it is a sealed chamber that might be used for vacuum processes and a spherical assembly in a large device that crackles with electricity, which seems to me to resemble the containment vessel of a theorized fusion reactor.

After the last teaser (opens in new tab), not a few fans have speculated that the creature shown must be aquatic in some way, and thus the expansion must explore (and exploit) the seas of Factorio's planet.

If you're a hardcore Factorio-head, or a game modding fanatic, go check out the full post (opens in new tab) to see the stats, including the rather shocking fact that over 25% of Factorio mods are 2,000+ downloads.