The Halo Universe has always been about variety.
Themed map packs (spaceship items, garage items, military items, office items, public places) would, immediately, change the feel of the game. Walking into a gray, Forerunner building is boring. Dodging a rocket launcher, by sprinting to a store sounds fun. People should be able to make a city map look like an urban city.
Themed climates. Arid desert, steaming jungles, harsh snow terrain.
Themed climate effects. Glittering snow, dust filtering into a burning building, rain!
Themed props. How about a dead marine? Or a dead Elite, scattered, here and there? A radio, a computer screen.
Eye pieces. Remember the cool holographic ring, on Condemned? Or the generator?
Low gravity zones.
Mold-able terrain. Start things flat, and then let forgers paint the landscape.
PROP PAINTBRUSHES. I want to rapidly place items.
