From the publisher's site...
Encounter the unknown. Sign in Stranger is a collaborative, long-term role-playing game of human first contact with aliens, and colonization of space.
Take the role of humans leaving Earth behind to create a colony on a planet inhabitated by sentient alien species. Choosing to leave an Earth isolated by quarantine, the humans must find ways to understand the incomprehensible beings they meet, and find a place for themselves in the new world around them.
Working together, players create a truly alien environment using mechanics inspired by mad-libs: random words are chosen as creative spring-boards for describing the beings and world around the humans. Play human colonists and aliens they encounter, as well as contacts on Earth, and people from the colonist's past in flash-backs to their time on Earth.
Intended for long-term play (over months or years), play of the game involves exploration and elaboration of many aspects of the alien world. Sign in Stranger can also be played in one sitting with the Quick-Start rules. It is a two or three player game.