In my opinion, Halo needs to be the best Halo game possible. Have the best campaign, have the best multiplayer that caters to both the ranked/competitive crowd and the casual/social crowd. This doesn't mean you copy CoD, it means you offer ranks, great custom settings, partner with MLG or have skills based tournaments. For the casual crowd, this like Infinity slayer, Fiesta, Flood, Grifball etc.
It needs to have firefight, needs to have campaign scoring and theater. You can't cut huge legacy/replay features and expect the game to be better than the last.
If you can't achieve 60 FPS, make sure that it's locked at 30+ at least. I should be able to split screen with 4 people on wreckage and all of us are firing fuel rod guns and it shouldn't dip below 30.
But I digress, Halo is not in the same position it was. Especially in the face of multiplatform games like Destiny, Battlefield, Call of Duty. And it makes a difference. Even Nintendo games have trouble. My younger cousins have a wii and a 360. They know what Skyrim is, they don't know what Skyward Sword is. That's the power of a multiplatform. More people know about it, hence more people want to play it.
And that's a pretty dumb thing to say right, but when you have 10 million+ buying Call of duty on all platforms at launch, the devs at 343 and Guerilla take notice and will then try to emulate because when you're in the business of making money, you want to make as much as possible, even if the game suffers.
