Prison Architect, which first surfaced in 2011, will finally be released at some point this year.
After numerous updates over the years, and over a million units sold, Introversion said a mobile version is also in development.
Prison Architect is still currently in alpha, and started life as a crowdfunding project on the developer's website garnering $270,000 within two weeks.
The alpha version has since sold 1,066,233 copies, and the team has raised over $9 million on the game.
The game was also one of the first Early Access titles to land on Steam when the service launched in early 2013.