Setting could be modern time or future time, doesn't matter.
Here we go;
- Cinematic\camera moves on to a big train station and moves thru 100's of people and then thru the glass window of the door as the door closes as the train is leaving.
- Now! There you are, standing on this huge two second floor train that has just left the train station for a long trip that will take a couple of days.
- You may see your own body when watching down, you have pockets that you can check and there you will find your identity as you have no memory of who you are and why you are on that train.
- You will have the entire huge two second floor train to discover that is full of people that goes on with their stuff, fighting over thing, talking about their last vacation or someone they love\hate, kids running around in the trian, you know, just full of life.
- *RING RING* what!? You have a phone in your inner pocket, you look at it and it's a unknown phone number and you answer it. "Hello?"
- *Caller* Listen, I only have a few seconds. There is a bomb on the train! Your the only one who can stop it, find the trigger-man *biiip* lines dead.
- Now you have to look for anyone suspicious, you will have many options to start dialogues with people, be social. Try find out who would want to bomb this train and why? When?
- As this is a long distance train, there is only 1 stop, one final destination so there is no way to leave the train. But that destination isn't before in couple of days. But you may search around, you have resturants, people have their small room to sleep in and there are showers, etc. Big train.
- Things move on, details, details.. Choices.. choices..
- You follow the wrong clue, the wrong person, the wrong girl, you think she is the trigger, you ask the wrong questions, you make a mistake, bomb goes off!
- You wake up in a hotel room, probably floor 16th, quite a view from there, in the city. Was it just a dream?
- As you get around, you'll notice people talking in the hallways, you take the elevator down to the ground floor and you'll be refused to leave like anyone else, the hotel has shutdown. Police detectives are investigating, you won't learn right away what is going, many ways you might figure out what is going on but something that happen or someone important is on that hotel and they won't let anyone leave.. What will you do?
- Explore 5 star hotel, they have EVERYTHING and people won't just sit around doing nothing as this might take a while, go check around, be your own detective. Break into hotel rooms, go thru peoples stuff to learn something or nothing. Details, details.
- You end up checking your own room you left so in a hurry, you find a sniper rifle, some knifes.. you have no idea why you have these stuff because you are just.. you are just.. can you even remember? *you pass out*
- Something bad is going to accour, you *snap* back to the hotel room again, you remember something... The girl, she called you -your name-.
Hm, but if you did actually found the bomb on the train and even got so far to defuse it as well! What would happen?
I can see all these different playthroughs.
Also, who the trigger-man is, would be random! Different each time.
But this is just the start 1\5 of the game, just a thought\idea I had that I don't think we will ever see

Hm, for the fun of it, what did you think?
Keywords, exploration (as in total freedom to go anywhere within a real big train and huge hotel with everything), choices, climix, mystery, puzzles, human interactions, social interactions, guns but very limited if you have one as people would react how they would in a real world, your in a hotel, gun, police, not so good idea? If you got away? But why shot anyone, who? What's the purpose, well you could shot someone random and try to get away with it, but you are still locked inside so what will you do? What kind of person are you?