Ben Robbins of ars ludi and lame mage productions is working on a game tentatively called microscope. It sounds entirely awesome.
You start by laying out a brief sketch of an interesting era. You might start with an idea for "the Imperial Dark Age, which began when the wormhole network collapsed, and ended when the fractured civilisations finally reconnected the network after centuries of rediscovery and war"; or it might be "the era of adventure and villainy on the high seas before the Ur-Kingdoms back home declared peace." Once you've got what happened on a large scale, you dive into the history and play out the how, and why, skipping around history to the interesting, pivotal moments in whatever order you like.
Ben has a pile of posts about microscope at the lame mage blog, but the capsule explanation of play that caught my imagination is in an ars ludi post about the implications of microscope for record keeping:
Once you do decide where in the history you’re looking, you focus there and it does become "now" for all intents and purposes of play and excitement. When you are playing out the scene where the civilian cargo ship suicide-rams the alien dreadnought during the last attack on Earth, you are playing in the moment, live or die. But then a minute later, when the scene is done, you step back ten thousand feet, look down on all creation, and decide where to look next. Zooming in and out and then in again. Like, um, a microscope.
That makes me want to play this game. It makes me want to play it so hard.
Needless to say, I'm going to be watching to see where this goes.