Select Skybox / Environment
Since it's all supposed to be a simulation, we should be able to change where the map is set. I want deep space, upper atmosphere, forests, deserts, beaches, underwater. All of the background stuff is built to be as gentle on the framerate as possible.
Easier Gametype/Spawn setup
I can't tell you how many times I've made a great map, gotten everything laid out perfectly, then lost interest in it completely because the process behind setting up gametypes and spawns is a god damned ordeal. I get the impression that even Bungie didn't know how to handle spawns in Forge, since the Cage exists.
Editable Textures/skins
All basic building blocks should have multiple textures to choose from, to get away from the gray-heavy forerunner pallet. Let us pick from flat (and then define the color via Object color), stone, brick, forerunner... whatever it takes so we can have some variety instead of a huge grey mess. This would go a long way towards maps with more distinguishable landmarks and more interesting visuals. We'll never be able to make a map on the same level as the built ins, but there's no reason we need to deal with Grey soup.
Terrain Deformation
Rather than a ForgeWorld with lots of terrain to pick from, just let us edit the terrain to our liking with rudimentary tools. If Farcry can do it, so can Halo. Gentle hills, steep canyon walls, narrow pathways, whatever. Tunnels and bridges can still be done via natural building blocks if that makes it easier.
Unlimited Pieces
Why can I only have 99 objects despite having a huge budget left? I can understand some of the larger pieces, vehicles, weapons, etc., but large chunks of rock? Large building blocks? Should be much higher piece counts or simply unlimited.
Object linking or Hierarchy
We need to be able to link multiple objects together for easier moving or editing. If I build a cool structure out of a couple dozen objects and then need to move everything a few feet left or up, I have to manually move each piece. We should be able to create groups and assign objects to them, or have some method of linking objects to each other (like touch-based, so any object that touches is considered 'linked').
Invisible Barriers
If you're gonna force jetpacks on us, give us a way to make maps without them having to be entirely enclosed. Kill barriers don't cut it. Terrain editing should let us take care of the horizontal movement, so give us something we can put overhead to keep people from cheesing our maps. Would also be nice for maps that we want to keep some parts open for (like beaches, but without letting people get way out in the water).
More Decor items
Players navigate maps via landmarks. Having colored orbs isn't gonna do the trick. We need things like trees, vines, waterfalls. Give us some big forerunner structures that serve no purpose other than to just sit there and let people orient themselves. And let us use more lights, preferably without crippling the framerate.
Shadows
Nothing in Forgeworld drops shadows. It makes that big grey mess even greyer and messier. Objects should drop shadows.
Definable liquids
Probably impossible (thus, why it's at the end here), but I would love it if we could have water, lava, mist or other liquid-like volumes. Have them adjustable like the shape of objectives (set the top, length, width, etc.). I'd love to have some underwater areas or a munitions factory with huge smelting pools.
