Looks like more and more devs realize that people enjoy a fight against something much, much bigger (well, at least when they can win against it) than what the player is controlling. This will eventually lead to fights against whole Galaxies or whatnots.
Though, all jokes or whatever the hell that was i just said aside, this did look nice, though i haven't heard of it before. The trailer made it seem like a co-op multiplayer game where the goal is to kill Hydras.
But as i said, i haven't heard of this before, so I might as well just guess randomly.