Halo is and always has been more of a multiplayer series from a quality standpoint anyway. Combat Evolved was the best the series has been campaign wise, and that shit had some incredibly shitty level design at times. The Sequels? More of the same, no fixes, bad level design, horrible story telling and writing that got fleshed out as opposed to being dialed back (CE in contrast had a great tone). So I give zero fucks about Halo 5's campaign.
Now Halo's multiplayer I give all of the fucks, and Halo 4 was not fun to me, but Halo 5's beta, the 20 launch maps and 15 free maps, the addition of Warzone, some of the new mechanics that fit Halo's style, them actually making assault rifles a more viable part of the sandbox (but still inferior to the BR/DMR) has me pretty positive. It won't be Halo 2, that was the peak of Halo, it was all downhill from there. But it'll be better than Halo 4 by a good fucking margin, and of the MP stuff this year, I'm looking forward towards more fucking Halo than more fucking Battlefield but with Star Wars.
I think CE shines best wen played in co-op on Heroic, no less. In that respect, it's pretty much my favorite first person shooter ever made. On normal difficulty, it just felt like an slog through endlessly repeating environments, despite its nice, memorable atmosphere that i appreciated. It's amazing how much of a different game it can be, blew me away wen i gave it a try.
As for this one, it looked nothing like the Halo i appreciate, but just like more of the same spectacle shit setpiece driven roller coaster i've seen in countless other shooters. Halo ended with the third entry.
It definitely had slick gameplay and a nice sense of progression to boot. It's up there with the original Half-Life and Doom.
The thing is Bungie fundamentally understands gameplay systems, and 343 doesn't. I could feel it in the singleplayer with their mission designs in Halo 4, but since systems is more fundamental in multiplayer, they dropped the ball big time.