(This is completely subjective)
Personally, I liked a lot the campaign of Halo 5. But it has many problems and weak points, and for me, they are:
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Anticlimactic final: So, we have defeated a Kraken, killed multiple Warden Eternals and we practically defeated the entire Covenant, what is the final threat? Nothing. We don’t have a final boss, we don’t have an epic escape with a Warthog and we don’t even have to shot anything in the final seconds. All we need to do is just run linearly to one objective and have a Cliffhanger. Disappointing. - Disappointing antagonists: Cortana is a… interesting antagonist. But we barely know how she come back due to the weird explanation that they give us. Warden Eternal is a pretty lame antagonist, it works well like a boss, but his personality is pretty boring and a lot of his dialogues are cheesy. Jul 'Mdama is by far, the worst antagonist of the Halo franchise, he don’t have a interesting personality, have a pretty weak design and have a ridiculous death. - The entire “Enemy Lines” level: This is pretty much the worst level of the campaign, is linear, barely happens something interesting and the Kraken can be defeated easily, even in Legendary. The only thing that saves the level is the awesome and beautiful sceneries, the use of Phaeton and the small Forerunner battle that we got in the ending. - Bad use/interpretation of characters: The entire Blue Team (except John) has a flat personality. Kelly, Fred and Linda does nothing important in the story, and they barely say something in the cutscenes.
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