Yup! All fixed. The only problem now (if it's a glitch) is there seems to be long pauses where nothing can be clicked. I like this game - it's not just good-for-a-first-attempt, it's just good. :)
Yeah, probably is 😄 I think the problem was that I thought I could only click when the cursor hand was open, and that when it closed it meant I was not over the clickable spot anymore, so I would click elsewhere - but now I see that it both opens and then shuts when it moves into the clickable spot. Also if I move the mouse across the spot the hand can then easily open while the mouse is over a different spot, so I had thought that the clickable spot was moving randomly and vanishing, when it just meant I had moved across the button from a different direction... but I'm rambling.
I suppose instead of markers, you could make the hand remain open on "mouseover", rather than opening and closing on "mousein", if that could be done? I haven't used Godot yet. :)