The actual modeling of the missile flying through the air is not modeled. However, the time between the firing of rounds, which replicates the time to load a round, acquire a target, and fire has always been modeled in ATF and AATF engine games. That is what I was talking about.
There is no DRM. That having been said, the license only authorizes you to install the game on only one computer at a time. Of course, the computer police aren't going to break down your door, or anything.