Longtime Halo player since original Halo: CE. Story arc using Cortana's latency issue was effective, kept you interested.
would have liked to see more of the bad guy's effect on earth / UNSC. 8 levels was too short by about 2 levels IMO. One more level where the jerk UNSC commander eats crow would have been nice. they made him a guy you like to hate.
Legendary difficulty just right, not as hard as Halo 2's sniper levels of death, but some challenging levels.
Multiplayer made more like COD which was good. no firefight mode though? Keep spartan Ops, but keep firefight. sometimes you don't want a story, just kill grunts.
Face capture tech and level detail / screens best in the series. Ending not as bad as H2, but nowhere near Halo: CE / H3 homage type tension. Don't know if that can ever be reached.