The project was called Backspace and was reportedly going to feature guns, time travel, and an alien invasion--all powered by The Elder Scrolls V: Skyrim's game engine, including its "Radiant AI" system.
Obsidian Entertainment CEO Feargus Urquhart confirmed the studio was working on the game, saying Backspace "was a project concept that we neither cancelled nor greenlit."
"We've been around for ten years now and have had a bunch of great ideas that we still have sitting around that we may be able to return to in the future," he added.
According to a design document obtained by Kotaku, Backspace was a single-player action-RPG set in a sci-fi space environment with "simple elements of time travel." The combat was reportedly paced "similarly to Skyrim, but slightly faster since there is no concept of blocking."
"The easiest way to look at it is a mix of Mass Effect, Borderlands, and System Shock 2 for gameplay and setting," the document reads.
Backspace was designed, according to the documents, casting players as a cyborg--90 percent human and 10 percent machine. The game was set in the "distant future" when mankind had colonized the "far reaches of the galaxy."
The game's story, according to the design documents, revolved around players jumping back and forth in time between the occurence of an alien attack and an alien-occupied future.
Backspace was also planned with a leveling system likened to that of Skyrim or Fallout: New Vegas, with players able to choose a preset background for their characters, including The Mad Scientist, The Lone Wolf, and The Arrogant Savant.
Combat in the game was reportedly "Skyrim with guns," with players able to wield machine guns, shotguns, semi-automatic rifles, sniper rifles, and rocket launchers--as well as melee weapons like mauls, battle axes, and chainsaws, among others.
Backspace is not the only unreleased project Obsidian Entertainment has spoken of. The Irvine, California-based developer also spent time developing a Snow White prequel and pitched an idea to the now-defunct LucasArts for a new Star Wars RPG.