This shit is off the fuckin' charts. I played for like four and a half hours yesterday, got about three hours in tonight, and my save progress said I'm like 78% complete.
It was hard to turn it off, but as it is, I'm only gonna be getting five hours of sleep before I gotta be up for work at 5:00. Oh well, I'll try to beat it tomorrow afternoon/evening and then get in some multiplayer Friday.