Prison Architect is still in alpha - but you really wouldn't know it. The game is as feature-rich as a complete product (moreso, if anything) and there are no game-breaking bugs.
So, what is it?
Prison Architect is a nod back to the micro-management games of old (I'm avoiding the word 'tycoon' because that has become a hackneyed term to mean simplified 'make lots of money' cartoon game). It's pure sandbox
so don't let the first 'mission' put you off. It did me (I didn't find it interesting) and didn't then play the game for a year or more, but that first mission is pure tutorial just to show you how the very simple tools work. You are then left on your own with a blank canvas and all the tools you'll need for designing your own prison.
How complicated is it?
It's not at all - but it can be if you want it to be. It's genius in design for that. You can be in the game and designing your own prison very quickly indeed without needing to be bogged down in all the minutiae of prisoner and roster management, but the beauty of the game is that, if you WANT that level of micro-management, you can. You can set individual punishments and such for prisoners, but you don't have to. You can schedule different daily timetables for each level of security prisoner so there are no clashes and inevitable riots, but you don't have to. You can individually manage reform program scheduling, but you don't have to. You get the idea. The game automates all these things by default, but allows you to override them if/when you want to.
Of course, getting a prison off the ground AND making money is that usual tycoon balancing act. You have to start building foundations, but you can't go too large too soon otherwise you will be bankrupt overnight (and game over). You can't expand one area too quickly (e.g. cells) unless you have the infrastructure in place to support them (bigger canteens, showers, and more utilities). And not everything is available to you right away: you unlock specialist staff and services as you go, providing a feeling of achievement on top of the creative aspect of the game. The fun is in finding that balance and making your very own Alcatraz (or Reform Centre if you feel like being a benevolent architect). The game scores you on the overall effectiveness of your prison (determined by how many riots and escapes you've had versus reformed and released prisoners unlikely to reoffend).
It's a PRISON game - how is that even fun?!
Oh, but it is! If you like designing and tweaking 'something', then this is your game. Maybe you played Rollercoaster Tycoon, or Transport Tycoon, or even Simcity or Theme Hospital. Bear in mind that it's pure sandbox (right now at least; I vaguely recall reading that missions might be added later but don't take my word for it). You have a planning tool that will allow you to freeform-design your layout without committing any money, then build on top of your design after. The fun is in creating a layout you want, and balancing it to make it work well (no good sticking a dining hall at the other end of the map if prisoners cannot reach it in their allotted mealtime slot).
About that 'alpha' thing...
Yeah, it's not even beta, but don't be fooled. This is in a better state than any other beta game I've tried. There are elements still to be finished (the execution chamber does nothing I believe, despite its appearance in the tutorial mission, and some things don't seem to have much effect on environment yet), but Introversion have been updating the game very regularly over two years. I joined the alpha at its earliest stage and still the updates come. Even if they didn't, this is a complete and playable game exactly as it is right now
, and I have close to 160 hours recorded in the Steam version alone.
The game has an incredibly open mod support scheme and there are plenty of popular mods in the Steam Workshop right now. I've tried the Women's Prison mod and it is easy to activate or deactivate each mod in the game. An excellent design. Of course, with the game changing periodically there is no guarantee that mods will continue to work for each iteration, but their easy removal means no worries.
Prison Architect is a game that most certainly doesn't feel like an alpha (or even beta). Get past the somewhat awkward-feeling introductory mission and you have all the tools needed to design your own prison. It's a micro-management sandbox simulator that's easy to get into, fun, and will inevitably sink far too many hours of your time! Highly recommended, and a great example of crowd-funding at its absolute best.