It reminds me of a harmonica in that it plays different notes depending on whether you blow or suck. Approximately: one direction gets you a major chord, the other the corresponding dominant. So playing something like a major scale would require confusing navigation around the two sets of notes. I had to make myself a chart. I found it a bit frustrating but obviously it would need more practice and I probably don't understand how it's typically meant to be played.
Not hard to play, sounds great. Be warned that this can be really, really loud in the hands of a sufficiently motivated toddler.
I'm kind of sad to see this gone. It's obviously extremely specialized--all it does is minor variations on a single drone. And I don't play the kind of music it's intended before. But it was still satisfying to turn it on and sing along with it.
Pretty similar to the companion "pocket piano": very portable; lots of variety possible from twiddling the knobs, which you can probably figure out just by blind experimentation, or you can consult the key.
It doesn't include a speaker. The included amp is certainly enough to hear what you're doing, but won't really give you any significant bass--using something else will make it sound much better.
I gave up trying to follow the story at some point and just looked at the art.
Maybe I should give it another shot. Druillet seems to be an important creator, I'm glad we have some of his work.