Trigger to next slide

You could give each shape a true/false variable. When a shape is clicked it goes true. When a shape is clicked it checks to see if all shapes are true.  If all are true then state of next button is normal (assuming you disabled when timeline starts). Or if you prefer to advance automatically, check if all are true and if so, jump to next slide when media completes.

The problem is that the object state turns to Visited as soon as it is clicked, and that causes the jump to the next slide. Perhaps the simplest solution is to write a trigger for each layer: Jump to next slide when media completes IF the state of each button is visited, That prevents the jump from happening prematurely, and allows the learner to visit the layers in any order.

Thank you so much! This looks to have worked.

So on my base layer I have the "show layer w, x, y, z" when user clicks a,b,c,d

then on each layer I have "play video when the timeline starts on this layer"

and finally the new trigger per layer as you mentioned.  Anything else needed besides the standard swipe for previous slide?

Thank you for your help!

Anything else needed?

Not if it works :)