Prison Architect ranked 68th in this year's PC Gamer Top 100. I reckon it might climb higher still in 2019, because, three years after full release, it's launched a multiplayer mode.
Currently in alpha, the jail sim's multiplayer mode comes with its Update 16 and lets players build prisons alongside seven mates. In public or private games, the alpha offers a restricted version of the base game in order to let the devs "focus on getting the core functionality working."
As such, some features are absent for now—such as wire connections, prison grading, reports and emergency callouts (these can be controlled but not called in), among other things. Producer Mark Morris and designer Chris Delay provide the following, typically funny, overview of what's in right now, and what's planned down the line.
"Our programmers have achieved the impossible, and grafted co-operative multiplayer into Prison Architect," reads the video's description. "Disclaimer: This is a very experimental alpha launch of multiplayer. You need to opt in to the steam 'beta' branch to gain access."
The developer says non-Steam players will be able to download the latest version of Prison Architect from the builds page in the next few days. Here's our review of the game Chris described as a "complex, challenging, and grimly satisfying simulator."