Rework the unlocking system for weapons, attachments and equipment. I don't like going against players with max-level loadouts when I'm stuck with no attachments because I decided to play a new class or gun. Have you considered why Halo doesn't lock weapons like this?

Add the random drop rewards like the first game.

Add the challenge-based skin unlocks like the first game. It encourages to play in different manner instead of monotonously grinding levels with the same gun.

Improve the portal-surface placement in the maps. I'm not asking to increase the amount to what it's like in the first game, I'm asking to check for positions where a portal-surface could be useful. There's many pockets of portal deadzone where there's no surface nearby or where I want to go. There's also cases of surface visibility and LOS, where I have to walk a few feet to put down one portal, then walk back to put the other portal because those surfaces aren't visible simultaneously. Perhaps this could be solved with the porta-portal, but I haven't unlocked it yet because of point #1.