Once Upon a Time in Roswell is playing on the severely underused ghosts vs aliens trope, in that the game will clearly be dealing with stuff that could go either way. While the developers aren't revealing anything spoiler-like, it all looks very intriguing.
There's a fair bit of mystery surrounding Once Upon a Time in Roswell, and while we haven't seen much gameplay just yet, we do know that it's going to be a first-person horror adventure with elements of combat. Think Alien: Isolation.
Once Upon a Time in Roswell's story will begin in the Peterson residence, where an entire family disappeared into thin air, and where the protagonist aims to conduct his search for them. That said, the game promises to also take us into Paris and Roswell itself, which makes us think there's no way there aren't aliens involved.
The heavy psychological slant suggests that the protagonist's encounters with extraterrestrials have a horrific effect in his psyche, which is where the game's "ghosts" may well be coming from. We'll see, of course, but it's a fun set up to think about.
The release of Once Upon a Time in Roswell is planned for late 2020, so we're a fair bit out still. Watch the trailer below to get a sense of what's what.