Introversion Software's Prison Architect has raised almost $8 million in revenue in just over one year since release.
More than 250,000 users have downloaded the alpha version of the game, which tasks players with managing a prison and is influenced by games such as Sim Hospital, Dwarf Fortress and Dungeon Keeper.
"This investment by our alpha customers is enabling us to turn Prison Architect into the game we envisioned without having to make any creative sacrifices or cut any corners - this is the very reason we're proud to be independent," said Introversion.
The standard alpha pack sells for $30, but the company also offered a handful of higher-priced options, such as a $10,000 deal that places the customer in the game.
Previous games from Introversion - Darwinia, Defcon and Multiwinia - have sold around 100,000 units each at various price points.