I just had an idea, not for a game but rather for altered perception on how the classic "Easy/medium/hard" difficulty settings that we've all grown accustomed to and probably take for granted.
Basically, instead of the game asking for what you think is the correct difficulty for you, it instead asks for your age. <12 is the 'easiest' setting, 12-16 would be the 'medium' setting, 16-21 would be the hardest setting (just because at this point a player's coordination has developed sufficiently, they've grown up in the digital age, and probably have the most free time to improve) and then >21 slowly tapers off the difficulty to account for an adult's likely decreasing amount of free time due to this stage in their lives when they pick up full time jobs, start a family, and other concerns that compound a need for easy-to-pickup games.
The largest trouble I see for this system are those that don't fit into the stereotypical demographics, 30 year olds that are actually dead beats that play videogames all day and want the hardest experience possible. Children that are gaming prodigies. High Schoolers that are just mentally challenged in some way. The only way I could see to work around that would be to provide full disclosure upfront on how the system works, but then I'd feel the game designer is being too intrusive in how s/he perceives the game player's life.
It'd be cool if it could be stretched to include the content of the story as well. Where very young players would have the story presented to them in simpler words and the theming of the story would be less complex for younger minds to grasp; whereas with an older player, the story is altered to be have dialogue that is freer to be witty and complicated, and have themes that an adult could understand and appreciate more fully. I'm not talking about just things like violence or nudity, but themes that are down-to-earth and personal that might distress a younger mind, like the difficulty of starting a family, how friendship fades away as you grow apart, the death of a parent or loved one (not violent death, but rather through aging or disease, where you actually have very little agency in their fate), substance abuse, things of that nature.
Just an idea, though obvious creating a game that had a dynamic story like that would probably would far too large of an undertaking even for a AAA game.