A first-person console shooter set within a persistent world, Destiny takes place in a future-vision of our own solar system: A great peace beamed across the system, after civilization spanned the galaxy.
This is where things get interesting. As in previous Bungie games, there'll be both a traditional competitive multiplayer mode and a "highly crafted" story campaign. But as I've touched on a few times now, that story campaign will be a far more open experience than anything the studio has done with Halo. Players venture from hub cities out to optional missions and activities on forgotten parts of Earth as well as remote planets. You might get there in a rinky-dink spaceship you bought by cashing in on the odd bounty, or in a highly customized interstellar luxury yacht you purchased after consistently dominating in competitive multiplayer. (Yes, there seems to be a shared currency between the various modes.)