Act 4 really ramped up the story with all the bloodshed, but the ending was a huge cliffhanger that's meant to be finished in Part 3, which is very annoying as someone who was dropped in the middle of the story. The first three acts just serve as set up and was boring as hell, with all the plotting and scheming everyone was planning, some of which feels completely unnecessary in hindsight (Like with Gloucester's wife getting arrested and exiled for practicing witchery? I know it was to foreshadow Suffolk's death, but using magic as a device to do so is such a weird choice).

Also, Henry VI, despite being the titular and most important character, doesn't really do anything. He's such a noncharacter, moved by the people around him rather than taking charge of his own story. Everything happening around him is far more interesting than Henry himself.