Prison Architect is an ever expanding incarceration management game, currently in alpha and on a monthly update schedule. If it's not growing fast enough for you, the most recent update adds something that will help: proper modding support.
Also, staff rooms, for when your little guards get sleepy. Come watch the update video.
Previously mods to the game needed to be hacked in for them to work, but the new system allows you to package them up and enable them from the menu. The video above shows Introversion testing the system with a few of the community made language packs, along with scenario mods that can provide structured challenges to players impatient for Prison Architect's campaign.
The staff rooms meanwhile are designed to allow your staff to rest, a consequence of a new fatigue system that was originally introduced for alpha 13's guard dogs.
Prison Architect already has Steam Workshop support, which thus far has been used to allow players to share their prisons. There are already a thousand or so available to download, the best of which Craig explore a couple of months ago.
Lastly, this new update brings a ton of performance improvements, allowing you to make larger prisons with larger populations without your rig grinding to a halt under the weight of so many criminals. That's sure to make the moment when everything goes inevitably wrong and riots break out everywhere even more catastrophic, as per Brendan's recent Prison Architect diary.