Genre: Platformer or Zelda-style overhead adventure
Inspiration: The Princess Bride.
Premise: An old man tells his grandson a tale from his youth, but as always, he may be exaggerating a little..
Setup: The game switches viewpoints periodically; one view is in the family home, where the grandfather tells the tale around the fire. The second view is from the grandfather’s POV within the story; you control him in his adventure as he relates it to the grandson.
Hook: Every once in a while, the grandson will call BS on parts of the story; in the middle of fighting a werewolf, say, the action will be interrupted by his dialogue, asking a question or poking a hole in the story. When this happens, the view may switch to the home; your character becomes the old man, and instead of swinging a sword at a werewolf, you are instead swinging a cane at a coat rack; when the action resumes, you may be fighting a mangy dog instead. Three towering bandits become a single pickpocket, etc. This might be a player-triggered event – a given key might cause the boy to interrupt, changing the nature of the fight you’re in (and the difficulty of it).
Twist: Partway through the tale, the old man’s son (the boy’s father) walks in and contradicts parts of the story. The setting and characters in the action sequence change to reflect this, as the son remembers events differently. Where the battle begins with the old man’s memory of a valiant fight against a werewolf, when the son resumes the tale it’s completely different – the father thumped his head and fell unconscious, and the boy instead repelled a mangy old wolf by throwing rocks at it (you, of course, control the boy).
Not sure how this would actually play out, but I like the idea of details changing on the fly due to an old man’s faulty recollection and tendency to exaggerate. Might be a fun one to try someday.