I think most of the hate comes from the Multiplayer.
To put it in perspective, certain details of the multiplayer leaked beforehand.
1. Random power weapon spawn at a random location
2. Killstreaks in the form of calling down weapon power ups and power weapons at your feet. The 3 you get to choose from were random.
4. Armor Abilities are back including a wallhack one.
5. Hitmarkers on grenades
6. Loadouts meaning not everyone has the same weapons. Certain weapon loadouts were tied to certain armor ability loadouts.
7. One of the loadout weapons was a one shot kill pocket shotgun
8. No de-scope when being shot at.
Coming from Halo 3 and Reach, at the time, these leaks were so outlandish they were actually laughed at for being fake. I mean some stuff, even tho all of these were widely hated among at least the core Halo community here, you could see. But Random Power weapons? Killstreaks? Loadouts? A one shot shotgun you can spawn with? To most fans this was essentially breaking core tenants of Halo and these had to be fake.
And they turn out to all be real. There was a very widely shared graph of the games population dive bombing after its launch window.
Pretty much. I actually perform better in Halo 4 than in any other Halo game. The guns feel nice and consistent. If the core gameplay had been traditional Halo, with normal weapon spawns and no loadouts, armor abilities, or perks, it would have been great.
But when things go wrong in Halo 4, they go spectacularly wrong. Entire teams with X-ray vision (a worse ability than Armor Lock) and Boltshots camping corners. An enemy getting a leg up when an Incinerator or Binary Rifle or some other super-weapon randomly spawns next to them. One team in general getting an even bigger advantage because they've been able to call in more ordnance purely by getting more points. It just got to be absolutely ridiculous sometimes. Also, it's easy to forget after four years of playing it on the MCC, but let's remember that Halo 4's loadout system had rank-based unlocks on the original 360 version. That means that players had to invest considerable time unlocking weapons, abilities, and perks, producing a severe COD-like imbalance where new players or players that didn't have as much time as others were at a disadvantage against those who had already sunk in a lot of time and have unlocked everything.
Oh, and the number of gametypes in multiplayer were greatly diminished.
Also, my complaints about Halo 4 extend beyond the multiplayer. 343i's art design was a radical and unwelcome break from the previously-established art style. The Campaign missions were painfully linear, plus there were QTEs (though fortunately not many). The AI took a step back from Reach's. The Promethean arsenal was largely just copies of UNSC and Covenant weapons, which was a missed opportunity for some truly unique weapons.
Halo 4 wasn't bad per se, but it was very disappointing.
