-Forge, with no/vastly expanded item limits and Forgeworld
-Maximum of 1 community voted Forge map in quick play rotation at a time which changes on a weekly basis
-Server browser
-Armor abilities as items, aka, single use with no recharge (except for maybe campaign use)
-No Promethean anything
-DRM and BR can both co-exist
-Elites, Flood, and Brutes as enemy types, alongside the other standards
-More involved Flood forms; maybe some get worse if left alone too long, maybe some combine, maybe some consist of multiple stages which get shot apart
-Duel wielding
-More open ended mission design like New Alexandria or Silent Cartographer
-Brief setpiece mixups like the Broadsword/space sequence in Reach, that wave defense part from Reach, using a mech suit in a darkened hanger against a Flood...flood, H3 Scarab fight, H4s big gun truck escort thingy, etc etc
-Weapons which elegantly contain secondary functionality, like the needler or EMP effect of the grenade launcher
-Warzone and invasion as gametypes
-Maybe sprint and maybe clamber? Probably just thrusting
-Any fights on a scarab/large machine should take the shifting of the machine across the terrain into account, not just a fancy looking basic platform. Think Uncharted 2 train level.
-One-shot for the campaign. If MC gets picked up somewhere, let them use warp, and then we can ride a drop pod into a base or whatever; maybe even steering it a bit to have some approach variety.