I really enjoyed the first five-ten hours but was pretty disappointed after that. Once you've screwed around in the open world for a few hours, the game really doesn't throw many new ideas at you. The last like 5 missions that are all linear were really boring and too many of the boss fights were bullet sponges.
It felt like if they came up with one or two more grapple-hook level tools, then polished a few more things, didn't repeat the same three environments the whole game, it would have been something really special. As it stands, it really falls short of what I thought it was trying to be. It's hard to finish the game and not feel like they were just trying to reach a minimal viable product.
It starts very strong, peaks early, and totally fizzles out in the end. There are so so so many great ideas and things that in isolation are fantastic (best hunters for sure, and enemy variety) but none of it quite gels together.
Imo the biggest problem is what smoke and mirrors the "open world" really is. The truth is that this isn't really an open world Halo so much as it is a fairly meh standard Halo campaign with a potentially cool but ultimately incomplete open world aspect sort of grafted onto it and it shows in the fact that so much of the plot happens in instanced sections and how little reason there is to go explore in the hub world.
Story wise I really think I'm done with this series...and that says a lot given just how formative it was to me (I have an entire library shelf full of Halo crap for fucks sake). Halo 5 may have sucked but the one genuinely cool idea that made it worthwhile was the epic Cortana heel turn and reveal of the ai as the dark horse faction of the universe.
Atriox is fine as a villain but goddamn it....the way they just retconned and handled all that shit off screen just leaves a bitter taste in my mouth.
Also where the fuck is the god-damned Arbiter, or Rtas, or the two elites who were part of your squad in Halo 3?!?
All in all...I checked out the legendary ending online already and I think if I'm ever going to sate my nostalgia I'll just play master chief collection.