What game? My wishlist is rather long, but here is a concept.
Not the top of the list, but I was surprised it wasn't done more
(I stumbled upon one (or two?) attempts in this direction, but it didn't tap the potential IMO).
A RPG (story, powering up by collecting objects / leveling up, etc)
where confrontations with hostile NPC is settled with a bejeweled like puzzle game
(i.e. match-three-by-swapping-tiles).
Minor detail: in what I propose, confrontations with NPC aren't necessarily a two-players adaptation of a single player puzzle game, with split screen and AI. None of that. Single player puzzle against time limits (or whatever it is that "games you over") is a better route in my opinion: why cram in a role for one extra player, if it has to be filled with AI anyway? There's still plenty of room to diversify enemies.
Here's what made me think this concept has lots of untapped potential.
Did anyone try the "Treasures of Montezuma"? It's a bejeweled-like game. I played a version distributed by PopCap.
Yes, I'm aware casual gaming is easy to dismiss as generally un-interesting, but good game design can be found anywhere.
Well, I had to admit it was extremely pleasing to play, because it is so nicely polished.
But the point is that it has a really neat design, with a large set of variegated special abilities progressively granted to the player to overcame stages with variations and increasingly difficulties. In short, a rich system of power-ups and special powers to be combined, for the player, and (to a minor degree) a rich system of difficulty elements to combine in the stages to be beaten.
And I'm sure both aspectys can be pushed further in this direction, with thoughts,
All this just cries to be used in a story and a RPG settings.
I'd like to see (or develop, if I could have a lot time
) a multiplayer strategic game like Medieval Total War, where each player can choose which aspect of the same faction manage...
As an example, player A pick faction 1 and wants to manage everything by himself (diplomatic, military, economic, etc); player B and C pick faction 2 and player B wants to manage economical aspects, while player C chooses military, and they demand all other aspects (diplomatic, exploring, ...) to the AI; player D picks faction 3 and wants to manage only military side, while all other aspects are demanded to the AI... and so on.
That's a very interesting concept, also adding that maybe two players could be in same faction (with different roles). I wonder if that could also apply in a massively multiplayer setup.