Bluetooth codec is to blame. Some Bluetooth codecs are (very) low latency.

I used my phone speaker. My daughter (5) loved it, thank you.

Was odd it only worked once in Firefox Mobille (Android). I had to install Vivaldi (badum-tsh) to get it to work again. Was a let down it was only one song.

There are more songs in the menu (I think).

Nope, coming soon. Was a disappointment for my kid after I told her there were more songs.

there are more. the menu is somewhat awkward. it wasn't working for me in chrome properly (wasn't able to choose other pieces). works ok in safari, had a blast with toccata and fugue in d minor.

I couldn't get it to work on mobile but I did get it to work in private Firefox window.