I'm not playing it - I don't do modern consoles - but it's amusing to sit and watch someone else play. The storytelling is generally well-integrated to the gameplay and there's enough shiny things on a big screen that a second person watching and just occasionally pointing 'Over there!' or 'Try X instead!' isn't completely useless. Missions are short and clear and it's easy to carve up into chunks so we can play a little now, stop when I get restless, and come back later.
So it's a share-y thing, unlike most of the games a certain someone has for his PS3 here, which I peer at for only a moment to note the graphics and then get bored.
... I still don't do modern consoles. I haven't appreciated these post-SNES enormous controllers!
(I should note that we're not that far into it now, because I have a limited attention span for sitting on the couch watching someone else do stuff. It may get more grindy and less funny later.)