Select multiple objects by dragging

Would be really cool!

Village / Town / City / World generation

a generator for creating bigger cities, with integration to go into rooms/buildings

Weather effects

Rain, snow, mist and other weather effects to add atmosphere to your map.

Secret doors

Make it possible that all doors can become secret. So, if the "box" is checked, one or both sides of the door looks like the wall it is made from. That way it is possible to have stone secret doors as well (it is fantasy after all..)

"Instant Dungeon" button (stretch goal)

A button that generates a dungeon for you with the click of one button.

Fog of (Not) War

I just had a good idea, but I don't know how feasible it is: a "Fog of War" setting so you can share your screen in games and use the animated, 3D map as a kind of guide for non-combat situations. For instance, if you want to show off a house to the party, but want it to be kept a secret until the reveal. The way this worked in my head is, it blurs walled rooms, until doors are opened to that room. This could also work in conjunction with roofing, using that to mask the rooms if it's a top floor. This came to me while I was showing off a building the party had made in Dungeon Alchemist and was trying to reveal it to them piece by piece. I basically zoomed in as much as possible to almost make it 1st Person, then opened doors and walked about the house, but a Fog setting could make reveals even more dramatic.

Object Rotation

As the title says, It would be nice to 3D rotate Objects, for example, make it seem like crystals grow out of walls or Books are Vertically floating or have something on an angle as in Crooked Currently, you have to have a separate object for Horizontal and Vertical items and that is if you can find both "states" for the object in question For example: building a Book-case Library Dome is impossible at the moment (unless you want it to look weird) Or posing a Pitcher in the Hands of an NPC-Model to indicate "Pouring"

Duplicate Room

A copy and paste option for rooms, where the walls, floors, and items are all copied, then the new version can be adjusted as necessary. Useful for any building with similar rooms (barracks, inns, etc) or for when you realized you built exactly what you wanted, but in the wrong part of the map.

Mirror / Flip object

I would love to see a feature to flip the orientation of an object in addition to rotating it. I wanted to try and make a grand stairway to a second floor and the closest thing I could think of would be to use 2 of the corner staircases side by side but I need them both to turn away from each other which doesn't seem like an option unfortunately.

"Seasons" slider

Adjust environment details to suggest a season. Fall leaves, snow, etc. This could be a slider in the environment settings, and/or an option during map generation. Maybe it could be disabled for more fine control over natural object appearance.

Doors set off center of grid.

If you have a two square hallway and want a door in the center of the end of the hallway it would have to be placed halfway between two squares.

Physics for water (and eventually lava)

Would love to be able to have pools of water at different levels that flow downward, as well as waterfalls and flowing rivers.

Isometric export

Lock Room against editing

Because Mistakes happen it would be nice to be able to lock a room against editing

Place doors without walls

To place a standalone door (like any other object) in the middle of nowhere. Acts as a surreal set piece, like a portal. This is similar to 'Objects not in rooms', but might be better as a separate post as I suspect doors are treated differently.

Group/Ungroup/Merge/Save objects together to make a Compound Object

Now that collisions are off (and once selecting multiple objects at once becomes a thing) I'd like to be able to group/ungroup them together so I can move them as a unit. And then if I'm sure that it's exactly the way I want it, perhaps to merge them together (though that may not be needed if I can just group and ungroup them).

Water Height & Color & Opacity

A slider to adjust the height to which water can fill to on a map, allowing for things like mostly dried rivers or lakes. I would love to also be able to adjust the hue of the natural water.

Chaos-Symmetry Slider

A way to tell the AI to make a room cluttered or orderly. The shack of an eccentric wizard might be cluttered but a church would have everything symmetrical

Custom graphics on banner / shield / coat of arms

It would be cool if there could be a way to import own pictures or graphics and put them on a banner / a shield.

WEBP

WEBP is a better format to use with VTTs. Please, add support to export as WEBP. https://developers.google.com/speed/webp