To start off, let me first just say I absolutely love this app. I have found it to be an incredibly fun and expletive way to learn to code and hope that in the future more languages will be added.
I did however have some troubles initially, that is until I found the support forums; so my suggestions are as follows:
As stated in every project, it starts off by saying “In this puzzle…”, and then shortly after in the ‘Instructions’ tells you exactly what you have to do without you necessarily having to think about it or actually treat it like a puzzle. I do think the instructions should be left where they are, but as a drop-down for added help if you’re struggling to figure out the puzzle on your own, instead of being readily visible - suggesting that that’s the approach you should be taking.
Possibly underneath the drop-down ‘Instructions’ box (or in some other obvious location), include a link called something along the lines of “Further Your Understanding” which would provide a direct link to the expanded explanations currently hidden away in the forums. Personally I have found that even when I feel comfortable with my understanding of a project I like to read the explanations regardless because they help to further expand upon and cement my knowledge of the concept being taught, and I am sure this would be beneficial for others as well.
In the forums underneath the explanation there is a dropdown tab called " Additional Code (hidden code that runs before the puzzle’s code) ". I have found on more than one occasion this information to be incredibly useful in understanding exactly what’s happening within the project. Most often there is code contained there that I do not understand (which I realize is why it’s intentionally hidden), however there is often information contained within (ie. array/object lists) that helps considerably with understanding what specifically is happening within the project. I have seen in the forums on more than one occasion that many people are not even aware of this and it has caused them unnecessary frustration, as it did initially for myself. It would be helpful to make it more obvious within the project page itself that (while still hidden as a clickable dropdown) this code does in fact exist, but is not required information for solving the puzzle itself, but is at least another available resource in understanding the puzzle, though again, not required.
Again, I love the obvious amount of passion and care put into creating this app and applaud the creators and all those involved, and hope that it will continually evolve into an even better, more accessible product for future users.