Update: Well, that didn't take long. Sega has officially announced Alien Isolation for Xbox One, PS4, PS3, Xbox 360, and PC. The first trailer is below.
Original article: Alien Isolation popped up on the Xbox Marketplace today. The listing for Creative Assembly's survival horror game includes the Xbox 360 box art along with several details and images.
The summary on Xbox.com (via NeoGAF) confirms previous reports that the game stars Amanda Ripley, daughter of Sigourney Weaver's character in the Alien film series:
"Discover the true meaning of fear in Alien: Isolation, a survival horror set in an atmosphere of constant dread and mortal danger. Fifteen years after the events of Alien, Ellen Ripley’s daughter, Amanda enters a desperate battle for survival, on a mission to unravel the truth behind her mother's disappearance. As Amanda, you will navigate through an increasingly volatile world as you find yourself confronted on all sides by a panicked, desperate population and an unpredictable, ruthless Alien."
Isolation sounds like the first Alien film or, to use a game comparison, System Shock 2. Amanda isn't a heavily-armed commando. The only gear she has is whatever she can scavenge from her environment. The Xbox Marketplace listing says that she's going to have to "improvise" and "use her wits" to survive.
Xbox Marketplace also mentions that the game will have DLC ("content downloads") and leaderboards. The latter surprises me. Survival horror doesn't seem like a genre that lends itself to high scores. That could be an indication that Isolation has a side mode of some kind, like BioShock Infinite's combat challenges.
It's interesting that the box art displayed is for Xbox 360. All we've heard about Isolation so far is that it's a next-gen title. I guess Sega wants to hedge their bets and release the game on current-gen consoles as well. A cross-gen launch seems fitting for a franchise as large as Alien.
While today's leak doesn't provide a lot of new information or assets if you've been following the coverage on this game, it does provide confirmation on the previous reports. The fact that Microsoft has a listing ready to go also suggests that Sega could formally announce the game real soon. Thus far, they've been unwilling to say anything about Creative Assembly's project.