I've started working on building a Soup engine/client/bowl/whatchamacallit in Godot 4, and I wanted to take note of some surprising things I've discovered along the way, both for my sake and anyone else attempting such a project. My goal is something simple like SOAP SOUP and SOUP ROOMS (i.e. all image based, four walls and a center art), but with some UI niceties for volume, room selection, and room editing.
First up, while there's a lot of support for sprite animation in 2D, there are no built-in solutions for animated textures in UI. This is obnoxious, but probably easy to work around with a script.
Second... there are a couple options for drawing the room boxes. It would be nice to use either CSGBox or a MeshInstance3D with a Box mesh, but neither of these allow for different textures to be applied to different faces. What I'm currently doing is 6 different MeshInstance3D's with Planes, but that means I have to resize and position them individually.
Third, billboard sprites (this is for the art and mini) can either be centered in both X and Y axes, or neither. When both are centered, the sprite is sunk halfway into the floor; when neither are centered, the image is off-center. I want it to only be X centered, which I guess means moving it by half its width, but my gut says this may cause problems when allowing the art to be scaled. There's a couple solutions for scaling, too: either the Transform scale, or SpriteBase3D lets the pixel scale be changed.
If I run across other surprises, I'll add them to this thread.