Plot hole: When Xander is driving onto the bridge, chased by the police cars, we see that there are police cars also blocking the end of the bridge to stop him getting away. How come none of them noticed the ruddy great ramp sitting alone in the middle of the bridge and moved it? It wouldn't take a genius to work out what he might do.
Plot hole: When Xander Cage is just about to try and get into the basement, two scientists walk out. One of the scientists says 'We are finished now - what about you?' The other scientist replies 'We will be done tomorrow' - yet just a few scenes later Yorgi uses the rocket to gas the whole room of scientists. How were they supposed to finish off their job?