This may be a stupid question but I've always wondered about it. In every single one of these types of games I have played the ships always have a top speed. Is this a gameplay decision because it was determined that it was just too hard to control otherwise or are there some real life physics at play here that I'm not aware of? From my limited understanding of how things work in a vacuum shouldn't how powerful the engines are merely limit your acceleration with the top speed being infinite? (at least until you get close to c anyway) Or is there some reason why a rocket can only propel a spaceship up to a particular speed like 220m/s?