System Shock is an FPS/action-adventure developed by Looking Glass Technologies and published by Origin Systems in 1994.
The year is 2072. A hacker has been caught trying to obtain secret corporate documents. A crooked executive offers to drop all charges, if the hacker agrees to hack their space station's AI so that he can steal a biological weapon. Big mistake: he wakes up six months later to find that all the crew members are dead, mutated, or roboticized.
The game had only modest sales, but the complex gameplay and elaborate worldbuilding made it a cult classic and critical darling. It is regarded as an influence to later games such as Thief, Deus Ex, Bioshock, and Dishonored.
Sequel and remake
System Shock 2 was released in 1999, again to great critical acclaim but disappointing sales. Looking Glass closed doors the following year.
Night Dive Studios acquired the rights to both games and re-released them on GOG and Steam, including an upgraded "Enhanced Edition" that improved performance and compatibility with modern systems. A fully modern remake on Unreal Engine 4 is currently in development.