Prison Architect: Mobile is launching a limited release in the Netherlands today in a throwback to its initial early access model.

Like its predecessor, Prison Architect: Mobile is a management simulation game by Introversion Software that’s centered around running and building a maximum security prison. The original Prison Architect won a 2016 British Academy of Film and Television Arts award in the Persistent Game category, and it received critical acclaim for its gameplay as well as its thought-provoking subject matter. New content and gameplay modes will be available in the mobile version as in-app purchases, though the game itself will be free to play, and it will launch worldwide at a later date.

When Prison Architect first released on PC in late 2015, it had already sold over 1.25 million copies throughout its development and on Steam Early Access, earning $19 million. Last year, Introversion Software teamed up with Double Eleven to port the game to console. For the mobile version of the game, Introversion Software partnering with Paradox Interactive.

Other games developed by Introversion Software include Uplink, a hacking simulator; and Darwinia, a strategy game that won the Seumas McNally Grand Prize at the 2006 Independent Games Festival. Paradox Interactive is an experienced publisher of strategy games such as Crusader Kings II, Stellaris, and Cities: Skylines.

It’s tough to stand out in the mobile market, which generated $41 billion in 2016 and is continuing to grow. According to Pocket Gamer, there’s currently 771,672 active games in the Apple App Store alone, with around 2,500 games submitted per month. In an industry report by Adobe, users are installing fewer new apps across the board, reflecting a mature mobile market that has become oversaturated. Retention rates have also reportedly continued to drop with each year, which can make it difficult for games that depend on in-app purchases and user interest in downloadable content.

GamesBeat reached out to Introversion Software for more details about the upcoming mobile release but has not heard back.