The idea I had was a setting where there's multiple planets that are habitable. Not, like, a ton, but like 2 or 3. Initial stages of the idea of terraforming, perhaps. And after spending about 40 or 50 gameplay hours on this one planet, it explodes, taking a few main characters with it. And then I was thinking of going into some really weird, Evangelion-esque psuedo-psychological "main characters lost walking around a white void" thing. Oh, hey, sorta like what happens after Sin kills people in FFX. Meanwhile, the story continues with the remaining characters on the other planet, and periodically they have dreams/nightmares about the people that died walking around in an endless white eternity. And then somehow, 20 or 30 gameplay hours in the story later, at the final battle, through a leap of faith (I'm still working out what kind of miracle this will be, and might go the "the world is what the main charcter imagines of it" approach, or perhaps a "love between to people is so strong it reaches beyond time and space" approach) the dead characters come back in the final battle, clad in stunning armor and glowing, making the perviously hopeless battle awesome and epic. And then their souls finally rest, making constellations in the sky.
I dunno. Just some random idea I was throwing around, lol.