For those of us who want to create these crazy contraptions or environmental elements, it would be nice if we could have stuff like cubes, spheres, cylinders, toruses and the like. If we're able to scale, parent/child and select materials for these primitives, that'd provide a lot more creative freedom than the yiffalicious 1 level and object set allowed. Bonus points if we're able to group them somehow and duplicate so that if someone makes, for example, a pillar out of cylinders, toruses and cubes, they can simply duplicate it around the level.
For the materials, ideally there would be a base set of textures for woods, metals, stones, and maybe synthetic materials. Then allow the user to modify the hues. That way instead of having to have 4 or 5 different materials in different shades, one or two metal materials for instance could then become steel, silver, gold, platinum, and so on.
If you guys are willing to take things even further, maybe allow users to mess with lighting on the maps if at all possible? Heck, while I'm asking for the moon here, might we even be provided with a blank map with as much control given to us as possible so that I might finally be able to spend 3 months creating that perfect night time garden or golden hour temple or dimly lit dungeon to make characters boink each other in? If that's too much though, I might be satisfied with a large warehouse to place lamps and primitives in.