Saga is exactly what it calls itself; given the scope and range of its tale it could be no less.
At times, it seems as though Brian K. Vaughn and Fiona Staples have not only thrown in the kitchen sink, but scooped out the garburator and pipes below. However, what seems a head-on collision between Warhammer, Starcraft, and Shadowrun reveals layers of interaction and a lot of thought behind its dizzying array of characters, factions, and locales. Blasters and organically grown spaceships, sorcery, robots, and ghosts all meet in the convergent chaos of its universe. Jarring at first, as the story reveals itself it is no longer so, the seemingly disparate bits build coherent bytes, growing in detail and interconnection.
With so many dishes spinning, it will be interesting to see how it unfolds in future. Sometimes difficult to categorize, if required to render classify it in a single phrase space opera would be closest — but not quite adequate.