"S.O.S., known in Japan as Septentrion (セプテントリオン), is a video game developed by Human Entertainment and published in 1994 by Vic Tokai for the Super NES. The game was later released as a sequel only in Japan for the PlayStation known as Septentrion: Out of the Blue.
Mostly inspired by the book and film The Poseidon Adventure, the players must escape the sinking ship Lady Crithania, which gets hit by a gigantic wave and is capsized, all within the time limit of an hour. However, the game is made more difficult by the lack of a visible timer (although it is shown if you injure yourself, in which case you'll lose five minutes) and the fact the ship rotates angles constantly and gradually gets filled with water.
The game features the possibility to play as four different characters, each one with the same gameplay control and same goal, but with a different story:
An example of the main game screen. Luke Haines stands in a stairway before the tidal wave.
Capris Wisher - An architect young man. He takes his younger sister Amy to the Lady Crithania. However, Amy's sickness becomes a severe hindrance to him.
Redwin Gardner - A counselor, he travels with his entire family, his wife and his children Stella and Harry. His nephew Jack is also traveling.
Jeffrey Howell - A senior doctor, he travels along his wife Adela.
Luke Haines - A crewman of the Lady Crithania. He suspects that the sea conditions are too much for the Lady Crithania to handle, much to the opposition of his superiors.
Each character can take up to seven other survivors, some of which have different value to each character, and all of them have different requirements in how to get to them and how to make them follow the player. Depending on how many survivors the player finds, who they are and how valuable they are to the character the gamer plays as, the ending will vary. Because of the massive amount of possible combinations of survivors at the end of the game, there are technically hundreds of endings to the game."
Source: Wikipedia, "SOS (video game)," available under the CC-BY-SA License.