The opening cutscene of the game is a man named Jacob Wyles. He's wearing a long brown trench coat. It's raining. He's walking down the streets as the credits are rolling. Eventually he's walking across the street when a car comes speeding by. Even though you see the driver clearly trying to break, the rain causes the tires to slip. It hits Jacob and he dies almost immediately. In this game, you play as Jacob. The next scene his him waking up "365 days ago."
No matter what you do, the fact that Jacob will die in exactly one year will not change. However, that is the only thing that will not change. The game has a lot more in line with something like The Sims, than the big budget shooters. The theme of choice is what the game delves into. Jacob is able to do many things in his last year of life depending on the player's choice. For example, he can try to rekindle with his divorced wife and make connections with his currently living child. Or he can meet someone new and maybe try to start a future with them. Jacob can become a local hero or a local pariah. He can get a great new job or become homeless. However, the brown trench coat doesn't leave Jacob's life. Every day it hangs on the coat rack by the exit door if Jacob doesn't choose to wear it (it's one of the few things in the house he cannot throw out or rearrange). And each new day begins by telling the date and "x number of days left."
The goal of the game is to question how meaningful a player's choices really are.And as such, some of the hardships of designing the game will come into fruition. The very first thing that a player will try to do is avoid getting Jacob killed, or try to kill him before the death date. Many things must be planned around making sure that the event happens without making the player feel limited—giving them the illusion of choice in certain places. The tricky part is getting the player to think about the life, rather than the death. Since that one thing is the one thing that is certain that will be their focal point until they are immersed enough to at least temporarily forget the death.
One of the ways to circumvent a player trying to circumvent the game is to use the titular "consequences." Since the majority of the game is focused around them, the majority of time and resources should be used and giving merit to as many actions as possible, and give them consequences that do not end in death and make sure that Jacob doesn't leave town. Sometimes it's easy: allow Jacob to travel, but all that would do for the player is cost Jacob's money and take away some time (maybe give a boost to a "happiness" mechanic though.) To make the choice to do that seem more meaningful and not just like a player punishment though, perhaps fill some photo albums that can be found around Jacob's house.
If the player decides to do literally nothing, Jacob won't be making any money and cannot pay his rent. He has a job and is able to afford everything he needs, but not everything he wants. The player can see Jacob work (the game should have a 1 IRL second equals 1 in-game minute), but always give the player the option to skip forward. It'd be an interesting experiment to see how often they actually use that feature, even if nothing significant happened that particular day. If Jacob can't pay his rent, then he becomes homeless (wearing that coat all the time). Another consequence if players decide to start doing "nothing" later on is that one of Jacob's friends or acquantainces may think that he's depressed and try to get him on the right track.
Another thing that must be accounted for is that the game needs to stop the player from trying to kill Jacob, without the game feeling like it's restricting them. It would be far too humorous for tone is Jacob found himself in a reverse "Final Destination" scenario. There are plenty of alternate scenarios that must be used in this situation. If Jacob attempts to kill himself, perhaps have him fail or have him wake up in a hospital, or stopped by a friend. Just create enough alternate scenarios to make the illusion that the choice matters. The developers need to be one step ahead of the player in this scenario.
The game isn't exactly about derping around until doomsday. Jacob does have needs, most notably a "happiness" meter and how much money he has. The player can choose to help Jacob get more happiness and/or earn more money, both of which do have use and where most of the gameplay should come from. Certain actions will give Jacob more or less money, and certain actions will give Jacob more or less happiness. As far a "meters" that should be the most. There's no need for something like a morality meter (although doing something like donating to charity may give a boost to the happiness meter). The game is not about the afterlife in any way whatsoever. The end is literally the end.
So then, what's the point of the game if literally nothing you do ultimately matters? Honestly, that's for the player themselves to figure out. People in the real world don't think about their own eventual death and choose to ignore it. However, in the realms of a video game you can give the player and exact time and let them figure it out in any way that they choose. Jacob can end up living his life as fully as possible in the short time he has. He can make up with the people in his past, or say whatever is on his mind. He can do charitable deeds or try and leave a legacy. Keep in mind though, that Jacob's knowledge of his death is not his, and he will not think of his own death (unless he actually becomes depressed in game). One of the more fascinating ideas I have for this game is being able to interact with the man who eventually runs you over.
It's oddly debatable whether this game should have an ending at all—besides Jacob getting killed by the car. If it does though, it's going to need to have multiple endings. Perhaps a funeral scene attended by those you interacted with in your last year, followed by an obituary that reflects your actions. It might reflect the themes of "what actually matters." It seems like a difficult game to make, but if done correctly it could be very moving and would definitely stray into themes that games don't usually go into. It might be able to be done in a movie or book, but it wouldn't be as powerful. Here, the player determines how to go about the situation and how they cope (or fail to) with their eventual death. The player decides what they would do in the situation of their upcoming death, whether they do nothing or everything, it's entirely up to them.