While I really enjoyed the movie, compared to the first one Age of Ultron is a mess. Way too much stuff happening. The first Avengers movie had the privilege of Phase I all leading directly to it - Phase II by comparison was a mess of different stories none of which have direct ties to the plot of Ultron, meaning that while the first flick had a large part of backstory already set up for it, Ultron has to do all the setup, introduce new characters, new villains and a new story all whilst maintaining a balance between the original characters. It does its best, but holy crap did it bite off way, WAY more than it could chew.