For me:
Visuals
Graphicwise and Aestheticwise, I wouldn’t mind it looking like CEA. Or better.
Im really hoping animations are breathtaking.
Campaign
I think we NEED something that’s amazing to play, and it should be like 40+ hrs. Something that opens us to a new world like CE.
And I think there should be plenty of easter eggs and a lot less boundarys so we can go exploring.
Multiplayer
MM should go back to 1-50, or even 1-100(if you are daring).
No more AAs, bring back Equipment and Dual Wielding. Dual Wielding would’ve been ALOT niftyer if the weapons dualable were better. Like in Reach, the Needler, Spiker, PP, Magnum, (and I think)the AR and the Energy Sword would have been cool to dual wield.
Equipment additions should include Hologram, the deployable sentennial from Halo 3s campaign and that temporary invincibility that Brutes used. An I kinda feel like Sprint is here to stay.
Customs need to be mingblowing ;). They should be extremely customizable.
Forge needs a makeover; no more grey! We should have Time of Day and Weather effects(as in changing skybox. Adding clouds makes it darker, and you can choose stuff to fall outta the sky like rain, snow, sand. Choose toughness. Choose wind. Add effects like fog and mist).
NOT FX FILTERS. FX changes the way the entire screen looks, and it’s stuff you can do by editing settings on your tv. Time of Day and Weather should ONLY affect the map.
Interactive objects like usable elevators, doors, and energy bridges.
Individual weapon modifyers would be nice. And I think instead of a budget or object limit, you should be able to add and add until your game freezes, but it’s on you because the game would warn you if you’re getting close to freezing/glitching/lagging your game.
For weapons, please for the love of god BRING BACK THE FLAMETHROWER AND FIREBOMBS!!!
Armory
Should be unlocked similar to Halo 3, but somehow merged with a cR system. We should be able to color individual armor pieces, and put camo patterns on them. We should be able to choose whether we want our Spartan to look like a shiny toy, or a battle hardened soldier. We should be able to buy Assassination animations, and Player Model held weapons. And I think Visor Types would be interesting. Mix and match types of Visors(default, monicle, eyes, robo eye, ect). As for anything else, look at BeniShroom’s “Armory Wishlist”.
New Stuff
-Flood FF
-A reverse FF where you play as the enemy an attack enemy AI.