Break down the Demo.
1. You travel from crash site to village. This can take 1 to 5 minutes. While traveling, you talk to someone over the radio and realize something is up (BUILD UP).
2. You arrive at the village and see erotica.
3. You're given a task to compete with shorty, to see who can get laid more.
4. You're thrust into a social dynamic, constantly talking to NPC, figuring out what they want, to get laid.
Break down the Sandbox.
1. Most content revolves around porn.
Now compare Demo and Sandbox content to single player game. The Demo blends erotica and pacing perfectly. You have a build up, then you see porn, then you enter an erotic social dynamic, with the goal of getting sex. Will single player story deviate from this formula? How different will it be from what's in the demo and what people make in the Sandbox?