By placing these digital crumbs, your supposed "free roaming" missions feel more like fetch errands. Each mission demands certain objectives be completed (usually locating something or blowing something into bits), but there are also a few optional tasks to complete. These blue radar blips don't require much extra effort, as they're just pickups that you walk over. Maybe that's fun for you, maybe not - the series has always leaned more towards arcade-style shooting than tactical thinking, so it's not a huge departure at all.
The mission content, however, is somewhat off from the regular series. A vast majority of later objectives revolve around taking and holding your ground as endless waves of troops crash against your squad. What that means in gameplay terms is waiting, waiting, waiting. You'll spend a lot of time simply standing still, waiting for a timer to click through its countdown and say you've taken the area. Then it's off to another blip on the map, where you get to wait some more. This is fine in multiplayer, where you're conquering as a team, but alone it's not excessively fun.
What really gets us though, is the campaign's length. We saved the world from Hitler's wrath in just over two hours, and we're not exactly crack troops. Then, curiously, the game said we'd only completed about 50% of the actual campaign. What it meant, though, is that we didn't get gold medals on every mission. Sorry, but the sameness of this outing wasn't compelling enough to bring us back into active service.