Oh I finished this on Normal on Release, and completed Legendary a few days ago solo...
Initially, I was a bit "WTF" on the whole thing. The end was very out "there" for my liking, with some pretty big leaps of faith 343i are hoping the audience will take. Plus it felt even shorter than Halo Reach for my liking. BUT, since playing through again on Legendary...the story has grown on me. I'm still a bit wtf on the ending, but I don't let it overshadow the rest of the game.
Multiplayer is both amazing and crap at the same time however. It plays so much nicer than Reach imo, the games are much faster paced (I like instant respawn) and it almost feels like Halo 2 again online. On the flip side, Infinity Slayer is fun, but I despise the lack of a classic slayer mode with AR/BR Starts and power weapons dotted around the map. Ordinance drops are ok I guess, but you can only pick one, its almost always a SAW and you have to get a kill streak to earn them. IS is good, but I still want to play Halo the the way it always played before.
Also, I'm already sick of fucking Haven and Complex. It's ALWAYS those 2 that come up and get chosen in IS. BTB is always Ragnarok. Yes, I get it, its been out a week, but it should have shipped with more maps, or at least more diverse maps. There's 3 freakin' forge worlds in 4, but none of those default maps show up in Infinity Slayer, why? Speaking of Forge, talk about 2 steps forward 3 steps back. Jesus christ, why have they removed the fine movement option you used to have from pressing down on the left stick?! And the zoom from the right. Now neither of these buttons do anything. Sure, there's "magnets", but they only work right half the time and when they dont your stuck fiddling around making huge movements when you only meant to move it an inch. Also, theres no human flying vehicles at all in MP (I miss the Falcon. And Hornet) even though people have been screaming about Pelicans, we finally get one in campaign but its not even a forge option in MP? Ffs. Also, you cannot co-op Spartan Ops missions on the same console, and you can't co-op campaign on the same console with 3 people either.
So yeah, for me it boils down to this: Halo 4 is
a great game, but if you've played and loved Reach you'll find they've changed a bunch of small things in forge and multiplayer which seem to serve no purpose other than annoying the living shit out of you.
Oh, and I miss invasion too. Dominion is bollocks compared to Invasion.
Still though, the campaign looked really nice anyway.