"We came on board to make a third person action adventure game, in the Call of Duty franchise, and we were working on it about six months." - Glen Schofield
"There are a lot of fans out there who enjoy games like Uncharted, so you can imagine that genre meeting a world-class franchise. We had a prototype together that was pretty compelling, and it looked really good. The opportunity to work on the biggest thing in the industry with... Infinity Ward, that's demonstrated that they know how to do exceptional software, was just an opportunity we couldn't (pass up)." - Michael Condrey

Just to get this straight, Sledgehammer was working on a Call of Duty spin-off action adventure game, but that idea was shelved when Sledghammer had the chance to work on...Call of Duty.