I find the object of the practice a bit misleading.
In the description, it said I need to change things in the Gem scene.
I thought I need not to do things about other scenes, but it won't meet all the goals.
So I go in and alter collision setting of Godot and BrokenWall.
The issue is that the instructions were confusing to you, the requirements weren't clear enough, right? I'm logging your feedback on our issue tracker to review for the next version of the course, thanks.
Just note that of course, it's best if people understand the requirements clearly from the start, but each student understands things differently, so we have to make many iterations and it's very difficult to make something clear to everyone. If you check the release changelog, you'll see we made many updates to the course already.
Anyway thanks for the report, we're now planning the course's remake in Godot 4, we're gathering all the feedback we can to hopefully make things clearer, more engaging, and more streamlined.