Adding the .mp3 audio I think is a really nice polish to show you can make things "feel" better with some simple Godot nodes and very straight forward code. I think biggest obstacle is students (myself very much included) is getting them think that for themselves. Which I'm sure just takes time, practice, and experimenting. My biggest issue with learning Godot so far is letting go of that fear of failure and just being willing to try things out and see what happens. I think that's just a after-effect of the the education system but that's outside of the scope of this feedback. I think this course is doing a great job getting me familiar with all the things I will need to start becoming proficient in Godot. Great stuff.
