The characters did not act like themselves, and it was frustrating to see they way they treated each other. I didn't like any of the main characters anymore.
Although Peeta was tortured to get back at Katniss, she refused to let him get close to her. Peeta thought Katniss was the enemy and she considered him another tragedy of the war. Without their love hanging in the balance, the fight against the government didn't seem to matter.
It was obvious from the beginning of the book that the rebels would be betrayed by the new leaders, but it wasn't developed sufficiently. It seemed like Suzanne Collins ran out of time and just tacked an ending onto the story.
I didn't believe Snow or Coin were fit leaders, but the people who could have been effective leaders, were killed. If these are the only two choices, everyone in all three books died in vain.
The last chapter of the book should have been a fitting conclusion to all Katniss and Peeta had sacrificed, but instead it felt like a Hollywood conclusion. I was disappointed in the whole book.