Tho I didn't play the alpha, just the beta I seen enough alpha footage to give a few examples - story mode was more complete, alpha players started as Lvl 3 and could only do the investigate the cosmodrome mission, beyond that they could also do explore mode and the strike. -PvP was all but the same, same maps same one mode. No iron banner event during the alpha tho So far as I know there was no other things that was different.