I was reflecting on one of the better campaigns I've run in the past couple of years, the Bjornaborg "Midnight but with vikings" game. I think if I were to do it again, I'd go further from the Midnight source. I've been reading the Eddas lately, and there're some interesting bits in the Voluspa and Vafthruthnismol about what happens after Ragnarok - Thor's sons and Odin's brothers survive and rebuild the realm of the gods, and the dragon Nidhogg rises against them, but the poem is cut short before that matter is concluded.
But it got me thinking - there's room after Ragnarok. Taking Norse mythology as a loose base and playing Ragnarok as even less of a victory for the Aesir, you end up in more typical OSR post-apocalypse territory. The giants set themselves up as petty kings over men, the dark elves of Niflheim gather slaves, the scaled spawn of Jormungandr and Nidhogg exact tribute, and the dead of Hel feast on the living. Where men gather, they are preyed upon. The old gods are dead, but in the hills their children hide among mortals, gathering worshipers and strength, prophecies and artifacts in preparation for a second day of reckoning. And unlike in Midnight proper, here such a thing is plausible, and perhaps foretold.
Upsides over Midnight: hope, no wizard-hunters, no orcs.
Downsides against Midnight: what do you fight at low levels if not orcs?, subtler pitch than "Tolkien but Sauron won".