They definitely rescued the campaign IMO. Multiplayer is missing quite a few features, though it is a load of fun as is and feels distinctly like Halo.
> a load of fun as is and feels distinctly like Halo.
Which is no small feat making a game that feels fun like Halo (as we remember it), without just retreading on the same themes. 343 could have made "another Halo game" and I don't it would have felt like Halo fun.