I was thinking of a game were you are using a computer console of some kind to tell your player (that would be a square, I guess) what do do and where to go. It would be an infiltration game, and the console would be really, really basic.
However, later on the game implies that you are telling actual people what to do, and when they die, they die for real, and all is an spy organization of some kind.
Each level would be unique, and if you die, you can't repeat the level unless you start the whole game over, implying, again, that the agent died.
If you do bad, at the end of the game you'd be discovered by the enemy organization and killed off, but you are never told everything.
If you do certain things you could also get some papers of the enemy organization with would tell you the back story, and that the agent would send you. But if you do this, the agent has to die or they would say something and you would be caught.
The real end? I don't think there'd be one. Just different endings, like being caught by the enemies, by your side or just doing all the missions perfect, or at least doing most.