It's a nice tool, didn't intend to come off that negatively. More of a thought experience about the limitations of these types of tools.
I'm not sure it's quite beginner level, as I don't see anything that shows you where the note is on the keyboard? You'd have to start with a bit of reading knowledge, or be willing to just hit random keys until you figure out the mappings.
If you notice the video linked (you really should not be downvoted for good input like this), then you'll notice that my son Luca is playing a piece which is fairly repetitive, but he did not have any instruction at all, the app helps you figure out what is where all by itself, 'random' keys will quickly guide you to the right keys. and then from there once you get the hang of it relative movement should come fairly naturally. The biggest hang-up is the piano keyboard itself with its unequal spacing between adjacent white keys.
HN can be weirdly sensitive to comments about music being hard; fundamentals being mandatory, etc. I bet if we criticized the code on Music News (not a real thing) it'd be the same way.
I'm not sure it's quite beginner level, as I don't see anything that shows you where the note is on the keyboard? You'd have to start with a bit of reading knowledge, or be willing to just hit random keys until you figure out the mappings.