Using realistic physics allows for nice tricks. In the video, you see how one ship flies and floats around while another ship tries to follow it by matching its own velocity and location to the target ship. Once it has achieved the same velocity as its target, it is free to rotate towards the target ship, in order to shoot at it, for example. Using realistic physics also gives rise to many nice side effects like the crash with an asteroid at 1:07. There is also a third ship following the second one to make the video more confusing.