Amnesia: The Dark Descent developer Frictional Games revealed that The Fullbright Company's indie hit Gone Home began life as an Amnesia mod, but switched to the Unity engine after plans to license Frictional's HPL2 engine fell through.

As a standard practice, Frictional Games co-founder Thomas Grip declines all HPL2 licensing requests, due to the engine's lack of documentation and support. After inquiring about licensing, Fullbright's Steve Gaynor received the same response from Grip, who advised the team to begin building Gone Home with Unity instead.

After following up with Gaynor in the months after Gone Home's release, Grip received a copy of Gone Home's original prototype version, which is now available for download as a mod for Amnesia.

While it's still in an early state, the prototype retains many of Gone Home's distinct themes and mechanics. "The prototype is quite short and very basic; it is really more of a proof of concept," Grip explains. "But it still gives a very good sense of the game, and having played the full version, I could recognize quite a bit. It does feel a bit awkward to play an early test like this though. Gone Home is a very personal game, and playing this prototype felt like a meta version of the game's voyeuristic thematics."