Having things like slopes and perhaps even half blocks would be nice.
Being able to rotate blocks would be nice too if that's something possible.

Maybe even placeable windows and doors would be nice. Like you could do 2x2 hole and put a window in it that you could interact with. Things like fences would be nice to have too. I think what i overall want is blocks that have unique shapes and or props that snap to grid so things like Fences are possible. Maybe make those moddable as well for creating your own props (unless that's already possible).

I'm enjoying this game so far!