I have played this game for a couple days now and have reached a few conclusions
Campaign-Good so far. It has returned to the open feeling of previous campaigns, in that you can approach the challenges presented in the way you want. I also enjoy the new enemies, they definitely have brought new life to the Halo Experience.
Graphics-Generally Good. Most of this game is absolutely gorgeous. My only criticism is that certain aspects of the multiplayer maps don’t looks as good as others.
Spartan Ops-Very Good. This is a great new addition to the Halo model and I have gotten a lot of enjoyment out of it so far.
Armor Abilities-Pretty good. It is an improvement on Reach, in that they affect the game but do not control it. Some need a little tweaking to make them even but in general I think they are well implemented.
Weapon Balance- A mix. I like the Buff for the Ar and the return of the battle rifle, but I think the primary weapons need some tweaking to be fully balanced. The power weapons are all pretty good, they give you a competitive advantage without being OP. However I do think they are a little too easy to obtain with the ordinance system.
Playlist Options and Custom Games-Poor. I’m hoping 343 has plans to introduce more playlists and Game options, because right now the selection is very limited compared to Reach and Halo. Where is Grifball and Snipers?
Forge-Pretty Good. While I Have not played around with forge much, I have heard the interface is quite nice, but the maps are not big enough. With any luck there will be some expansions in the future to allow for larger creations.
Overall I have enjoyed this game. The new additions have added to the game in my opinion, and it feels mostly like a Halo Game. While there is some definite room for improvement, I am happy with it so far.