I am benefitting from the Skill Map progression. I will admit this step is the least clear, but I get it now. =] I do have a clarifying question, since I will want to instruct my students before they reach this step.
When they add the “on sprite overlaps” event handler, would it be true to say this: There are kinds of sprites. You have used two here: a player sprite and projectile sprites. You choose the kinds of sprites the overlap event handler will be listening for. Because there are multiple projectile sprites in the game, there has to be a way to identify each of those individual sprites. For example, if you catch one projectile, and another one disappears, that makes no sense! When the event handler is triggered, the information to identify the right projectile sprite will be placed in the red oval called “other sprite.” You can make a copy of this variable and use it inside the event handler function to make sure you are making the projectile you caught is the same one that disappears.