So I finished the campaign earlier today, and I'm glad to say I'm really impressed by what 343i have managed to put together. The gameplay is best-in-class, and just so much fun at 60 frames per second. It literally never drops a frame. So damn smooth!
Things that really impressed me:
The gameplay; it's absolutely fantastic, and the game is so much fun to play. I haven't had this much fun with a shooter since the very first Crysis. A flawless exhibition of first person shooter gameplay.
Level design. Holy shit, the levels are massive, and that verticality. Climbing up to higher ground, and doing a successful ground pound is one of the most satisfying feelings in a game. There are so many different paths you can take to flank the enemy. So many different strategies you can employ. I really enjoyed the vehicle combat as well. Apart from the level design, the encounter design is top notch. There is never a boring moment in the campaign.
Art direction and visuals: I'm not afraid to say that Halo 5 has some of the most gorgeous art direction I've seen in a game. Some of the levels look mind-blowingly stunning, A couple of levels in particular had my jaw dropped on the floor. So pretty! I'd also like to mention the 30FPS cutscenes. The cutscenes in this game are some of the most impressive looking cutscenes I've ever seen in a game. It makes me wonder what the game could have looked like if it were a 1080p 30FPS game.
Things I didn't like:
The story. It doesn't make a lot of sense, Team Osiris never gets any real development, Blue Team hardly gets any screen time, disappointing ending--it all just doesn't come together as well as you'd want it to. I don't know about others, but the story did absolutely nothing for me, and I don't think I'll even remember much of it in a couple of weeks. It's very weak and very forgettable. Buck was the only character in the game that I liked, to be honest.
The length, I guess? I thought it was a bit short. I play these games for the campaigns so I'm a tad disappointed there.
Overall, I'd rate the campaign a solid 8.5/10. There are many moments of greatness, the gameplay is a fucking blast, and pretty much everything is where you'd want it to be except the story. I hope 343i hire better writers for their next game, so we can have the ultimate Halo campaign, because despite my complaints with the story, this is hands down, the most enjoyable Halo campaign I've played from a pure gameplay perspective. Bungie got nothing on this.
I'm gonna give the multiplayer a shot in a couple of days, but that's not what I play these games for. I'll probably play through the campaign one more time in co-op mode though.