"L'audace, l'audace, toujours l'audace."
So lets be frank: taking your uber-successful franchise, removing its almost-as-famous-as-Mario main character, making it prequel, and finally setting it an story that millions of people already know ends in tragedy and loss? That takes some balls. But, unlike the franchise's last two experiments, ODST and Wars, this is an balls-to-the-walls, edge of your seat, visceral success.
So what's to like? Well, if you have actually enjoyed the single-player campaign experience of the previous games, you will be rewarded. There is a story, a pretty good one. It goes some weird places at times, but that is to be expected. But it takes you some varied places too, from the space mission, which is cool but limited, and even a some stealthier missions, if by stealth you mean tag-teaming dudes with sniper rifles from afar.
Speaking of tag-teaming, I really enjoyed the squad elements in the game. There is no teammate control, just some really, really well done AI. You never feel like you have to escort Noble team, that they are holding you back; nor however are they unstoppable Übermensch that you can hide behind until everyone is dead. Sometimes you'll fight along side the whole of Noble Team, sometimes just you and a buddy, and sometimes you'll have entire platoons of UNSC Army dudes helping out until they get slaughtered. Because keep in mind, there is a damn WAR going on around you. You are usually on the periphery of it, but it is there, and people are dieing. It really adds some atmosphere and scale to the maps.
Gameplay wise, again, if you liked Halo 1, 2, 3 and/or ODST's campaign and coop, you'll still love this. The controls are as tight as a console game gets, the guns have a good punch and BOOM to them, and the Armor Abilities can change up how you fight dramatically. Because this is a prequel, the shield and armor system is closer to Halo:CE, than Halo 3. This change is softened by the buddy AI that is fighting and soaking up needles beside you, but you will find yourself pausing to recharge a lot. Run, gun, breath is the way to play. Also, run, brutal melee-assassination, breath is a good strategy too.
Hey, you like Firefight? Firefight is better. It has match-making, so you can actually find some games to play. It can be shorter, which is a lot more manageable and reasonable. Also, there is a mode that lets you or some other person spawn as part of the horde wave, which can be a huge pain in the ass, or really awesome depending on the players. People tired of playing with Cabooses in Slayer may get a lot of play out of the new Firefight.
So yeah, about Multiplayer... I haven't played a Halo multiplayer match since running the original game on system link in my dorm. Not my cup of tea(baggin) anymore. If you liked it before, you likely won't even read this review: you're out camping for a pre-ordered Legendary midnight copy. It isn't broke, afaik, so I don't think they fixed it.
In sum, Bungie managed the audacity to end their series run with a prequal, with a story that's been told already, about a completely different character. They had the audacity to go back in time, but find more guns to add (it's the army, not Marines, duh,) and give them to a Squad. But they also had the l'audace to make it a freaking good game. Also? Thermopylae .