As a Halo game, it's terrible and disappointing, as its own, it's a really good game
Story: Very simple, Cortana is falling into rampancy and the Master Chief has to return to Earth to find Halsey so she can fix Cortana, at the same time they and the UNSC ship Infinity get sucked into a Forerunner planet called Requiem, there they find the Prometheans and the Didact, which pretty much just want to destroy Earth and blah blah blah i won't spoil it for you, the story is actually really good; i have some complains about the story however, the Chief talks way too much, remember how silent the Chief was in previous Halos? There was a reason for that 343, Bungie wanted players to feel like the Chief and immerse more in the character, also, how did his armor change? Cortana updated his armor's firmware, but did that also changed it physically? How?, and why are Elites bad again? "Many things can happen in 4 years"? Like what? "I thought we had a truce with the Covenant"? Uhh... i thought you only had a truce with the Elites, also, what happened to Brutes? and how did the Prometheans and the Covenant join forces? Would you mind explaining?.
Graphics: Oh man, the graphics in this game are AMAZING, excellent job there 343, especially with the cutscenes, they are just simply amazing, a lot of detail put into almost anything, i'm surprised the Xbox 360 can handle such amazing graphics, only problem, the frame rate goes down sometimes when playing split-screen; and another problem, the new Spartans, Spartan IV, they are ugly, extremely ugly, Reach's Spartans were perfect, they looked awesome, and then in Halo 4 they come with this? Disgraceful...
Audio: I'm not happy with the audio in this game, the music is... bad and really generic and there's no Halo theme (Only in one part, for like 10 seconds, and it sounds bad too anyways), there are about only 2 tracks in the whole game that i like, both are from the Main Menu (Infinity menu and another one (Not the one when you start the game)), it simply doesn't match the masterpieces of Martin O' Donnell, Michael Salvatori and Stephen Rippy (Halo Wars), also, there A LOT of unnecessary audio changes in the game, a perfect example is the shield recharging sound, was it necessary to change it? Thanks for ruining a tradition that was in all Halo games (Except for ODST but that was because you didn't play as Spartans).
Gameplay: And now for the most important aspect of the game... i must say, if you thought Reach didn't feel like Halo at all, then you're gonna hate Halo 4, and if also you hated Sprinting and Armor Abilities, then you're gonna hate it even more since Sprint is now a default gameplay function and there are more Armor Abilities, the game pretty much plays like Halo: Reach, but now there are some changes in weapons, the Beam Rifle returns replacing the Focus Rifle, the Covenant Carbine returns replacing the Needle Rifle (Which is a shame for me since i prefer the Needle Rifle over the Carbine), the Plasma Repeater got replaced by the Storm Rifle (Which is pretty much the same thing except that you can't reload it or cool it) and the Needler is extremely overpowered, there are a new set of weapons, the Forerunner or Promethean weapons... i don't like them, they're useless in Multiplayer, except for the Incineration Cannon and the sniper (I forgot its name), there are new Armor Abilities, the noobish Promethean Vision, the noobish Hardlight Shield and the useless Autosentry; some Armor Abilities were removed, for example, obviously Sprint, Drop Shield, Armor Lock (THANK YOU 343!!!) and Evade was replaced by the extremely useless and awful Thruster Pack, some Armor Abilities were changed, for example the Active Camo was made even more noobish by making the radar only have white dots instead of red and yellow dots (Yeah, those white dots will really confuse the user lol), Jet Pack flies higher but is less annoying than Reach's Jet Pack, and Hologram is way more useful now since your reticle now becomes red when you target a hologram and they appear as enemies in the radar (Well done 343, now i have a reason to use the Hologram); there are new enemies in the campaign, the Prometheans, yeah... they're annoying and not fun, Promethean Knights will teleport when you try to shoot them and they only make you waste ammo, they will also grenade spam the whole time, and also, before you kill one, make sure you kill one of their Watchers, as they will revive dead Knights, now talking about Watchers, they're another ammo waster, they will flee when you shoot them and sometimes you will lose them, this is really an annoying problem on Legendary (Even with those problems, Legendary is still too easy), in other words, Prometheans are not fun, however, the most fun parts of the campaign is when you fight against the Covenant, i really enjoyed those parts! But then the Prometheans would arrive to ruin the fun... BOO! Killjoy!; also, Legendary is way too easy, just by telling you this, you will get an idea of how easy it is, remember how when playing Legendary on Reach it would take like 4 or 5 sniper rounds to kill an Elite? Well, here all it takes is 2 or 3; one last thing i would like to point out about the gameplay is... why hasn't Dual Wielding returned? Since Halo 3: ODST, Dual Wielding was removed... why? Dual Wielding was awesome! I want to see Dual Wielding in Halo 5, 343!.
Now, let's talk about Firefight... oh wait, it got replaced by Spartan Ops, yup no Firefight, i hope you're not upset about that, if you are, then uhh... deal with it? I don't know, blame 343... so let's talk about Spartan Ops, if you have played Special Ops from the Call of Duty series well then... it's pretty much the same thing, just with Halo on it, it's a side story with missions, but unlike Spec Ops, Spartan Ops has no challenge at all, why? Because of one simple thing, you can't die, well... you can, but you don't restart at the last checkpoint, you respawn immediately, major flaw there, but it's still fun. Forge is pretty much the same as Reach and 3, but sadly there's no Forge World or something similar, this is terrible for Forgers like me, we need a Forge World NOW!!!; and lastly, i haven't used Theater, but i've heard that you can't watch Campaign clips anymore, which is stupid.
Other: There are some other details i would like to point out, i mentioned before that Spartans IV were ugly, but let me explain why, they look like robots, it doesn't even look like they're humans wearing armor anymore, the helmets are horrible and look deformed, some torso pieces are just... exaggerated, and well... maybe there's just too much customization, i don't know, they're terrible and i don't like them. Talking more about Multiplayer, remember how the ranking system worked before? Awesome emblems everytime you ranked up, you really felt rewarded when you ranked up, but now... no ranks, just boring numbers, ever since Gears of War 2 did that, a lot of games seem to do that, why? I don't feel rewarded anymore when i rank up, you don't get that feeling of "Ohh i wonder what the next rank looks like..." anymore, if you're rank 29, you obviously know the next "rank" is 30, boring, and yes i am aware that Halo 2's rank system had numbers too, but at least the last ranks were emblems. And one last thing i forgot to mention when i posted this review, custom loadouts is terrible idea, as if Reach wasn't balanced enough because of Armor Abilities, now you can make your own loadout, that's good and bad, good because well... you finally can start with the weapon you want, but bad because it's not balanced anymore, remember back in Halo 3? Everyone started with the same weapons in Team Slayer, there was no excuse if you were bad, you just needed to get better, but in Halo: Reach you could have an excuse, for example: Jet Pack and Armor Lock, now in Halo 4, you can blame that the player had an overpowered weapon, and if you're a new player, you're forced to start with the Assault Rifle, no mercy for new players.
The good:
*Amazing graphics
*Good story
*Multiplayer is still addicting
*Spartan Ops is fun
*Barely any glitches
*Fighting against the Covenant is fun as always
The bad:
*A lot of questions unanswered
*Doesn't feel like Halo anymore
*Prometheans are annoying
*Spartans are ugly
*Music is terrible
Overall: 6.5 as a Halo game, and 9.0 as its own game.
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343, you made me feel bad when you said "Thank you for your trust" in the ending message :(