How do I create a Trigger to move to the next slide only after all Hot spots have been clicked on?

Two problems with these triggers , and the ones like them on the other layers:

The biggest problem is that once the jump to trigger is executed, all the rest of the triggers that fire when the user clicks Button 1 are ignored. So the variable is not changed, and the End layer trigger is not evaluated to see if it should be shown or not. This is a really valuable piece of information for every spot in a project, that once a jump to trigger is encountered, none of the triggers below it are executed.

In this particular case, I would not jump to this slide, I would just Hide this layer. Changing between layers and the base does not interrupt a chain of triggers. In this case, it would also allow you to create a visited state that could be applied to either the rectangles, or the underlying png. If you change the png, you would need a trigger to do that, and I would recommend a custom name for the state. Creating triggers to duplicated the built-in functions can cause conflicts.

Another thought is that you could get by without the End Layer, unless you have additional information to present there. Instead of showing that layer, the other layers can jump to the next slide if all the variables are true, or they can hide themselves and show the NEXT button.

I roughly applied a couple of those ideas to the two lower puzzle pieces, so you can see them in action.