Every game developer will have worked on at least one game that never made it to market, and in the case of Pentiment director Josh Sawyer, his most significant cancelled game was focused on the famous Aliens cinematic property.
Obsidian's Aliens: Crucible was intended to be a third-person RPG for PC, Xbox 360 and PlayStation 3 and was first announced in 2006. Publisher Sega would eventually pull the plug on the project in 2009, apparently because Creative Assembly's Alien: Isolation was also in the works at the time.
Speaking on Twitter, Sawyer explained what went down:
I got to work on an Aliens RPG for SEGA from 2006-2009. Obsidian didn't have directors at that time, just leads who were all considered peers. It resulted in a lot of dysfunction when the leads didn't agree on how to do something.
Progress on the game was very slow, especially when it came to creating workable game levels. We had another game in development with SEGA at the time, Alpha Protocol, and SEGA (understandably, IMO) shelved Aliens in favor of AP.
There were a lot of cool ideas in the works, but you don't ship ideas! The biggest lesson I learned from the experience is that if you don't have playable levels, you don't have much of a game (there are some exceptions, of course).
I was happy to play Aliens: Fireteam Elite because the overall setup was similar: small team, 3rd person, with an emphasis on deployables and support actions. The similarities ended there, but it was nice to see the idea could actually be fun in practice.