Thanks for the feedback! That's definitely something we could do better with the UI. Maybe we could add something like a color highlight around an object when you look at it or even a bit of text to pop up saying if it's scalable/can't be scaled. We kind of wanted to hide the hole in the wall as a scalable at first but this is probably an area where being more generous is better.
I was worried when we first had the idea that the core mechanic would be too shallow but a lot of the puzzles ended up really designing themselves it felt like. So I'm glad the depth came across to you as well and not just us while designing. Always hard to tell if it just seemed interesting to us or if it would be entertaining for others too.