This all sounds good in theory, but how does it actually play out? The first level we tried began in the sky. After jumping out of the plane and watching scores of other paratroopers land on their targets, we chose to crash right on the roof of a Nazi nest. As you might expect, the roof couldn't hold our weight and broke apart. Now on the top floor of a blown-out house, we snuck up behind the enemy and put 'em down. Had we landed out in the open, these guys would already be chucking grenades and calling for help.
These little choices will show up throughout each level. Head right and you'll come face to face with a crazed chaingunner; go left and you'll find a path that puts you at his vulnerable side, letting you clear the way for further exploration. There's still only one final end to each mission, but the course you take could be one of several different routes.
As for your weapons, the Allied arms get an extra boost by way of customizable parts. Some guns can have scopes attached to them (like the M1Garand rifle), but only if you find the necessary parts scattered throughout the mission grounds. Stolen Nazi weapons, on the other hand, are as-is and cannot be modified.