Time to die.
SSO contains player elimination. For those who haven't immediately sworn to never have anything to do with the game on that basis, let me justify such a blasphemy to the world of modern gaming.
Firstly, SSO elimination is both largely theoretical and almost always a harbinger of total defeat. Your teammates will always have the option to return you to the game unless they are only a few turns from collectively losing, so elimination is unlikely to last for long. Throughout playtesting few players have even been eliminated and none more than two or three turns before the game ends.
Secondly, SSO is a game of death and sacrifice, there will come games where players have the option to take one for the team, a noble sacrifice. That sacrifice can only have dramatic tension, fear and pathos if it has at least the potential to actually result in loss. That loss has to be player elimination.