London has fallen is not good as olympus.it lacks the benefits offered by olympus constricted setting but it also cant recreate the supervising brutality and lack of respect for human life olympus featured though it certainly tries we can understand in simple way that if olympus was the movie ROCKY then london has fallen is ROCKY3 this is a dumb analogy but you get the point.
ONCE the opening half hour sets everything up this is a non stop action movie which filled with gross politics.if ur a fan of gerraf buttler go watch the movie and if u r looking for a movie with no use of brain or we can say brainless action than this is the movie .