(See what I did there?)
Ok but seriously, the reviews so far have mostly made the multiplayer seem like a throwaway bit of fluff on an otherwise great game, but I am totally psyched about this map editor thing.
It's not even just multiplayer! You can literally make your own levels to playthrough, which by definition means this is more of a Sandbox than almost any other Sandbox game ever. You are creating your own virtual play scenarios.
And holy shit do they give you a lot of stuff to play with. It's like they hired half the people who made the Sims games and made them just do that again, but decided to let you run around shooting everyone in the houses you build. Which, really, is the natural progression for the Sims anyway. You could easily spend days fiddling around with all this shit.
Of course, we can all see where this is going, right? Vinny's Law dictates any level creator will result in a recreation of 1-1 from Mario, but with all the shit they're giving us here, I expect there's going to be dozens of recreations of the LOST island. I will be sorely disappointed if I do not get a CTF level with flags at the Beach and the Other's compound.