First off, thank you to the CodeCademy team for creating an excellent platform for learning code. Especially for kids, I believe the potential here is huge.
The other issue that I ran into is how if you click Run several times, it offers to give you the code. While this probably is not an issue for very disciplined folk, for kids this can be too tempting to pass up, and my concern is younger learners may take that option and then feel stumped in the next exercise when they need to understand it. In addition, when you hit Get Code, instead of showing you the code in a separate window so you can compare your code to the answer, learn from it, and fix it, it replaces all your code, so it’s much more difficult to narrow down where you went wrong, and learners may be tempted to just roll with it instead of finding why they were wrong.