The thing about even massive fictitious space ships is that it takes a ridiculous amount of fictitious time and fictitious manpower to construct them. Take Halo 4's UNSC Infinity, for example. It's not like you can just imagine it and it exists - no, you've got to deal with non-existent labor unions and the like.

But, hey, all that trouble seems like it'll be worth it for War Games and Spartan Ops, Halo 4's expanded multiplayer modes offering weekly co-op missions and deep character progression system.