First of all, I think the fact that you are using your own tool is cool and creative, but I can't tab out of it and still have the songs play in the background which is a pretty big accessibility issue (I'm using Firefox, don't know if other browsers work fine). It wouldn't be a big deal if you also had other ways to access the music (streaming, download) but the fact that it's the only way to listen to this its quite a bummer.
Ok let's talk about the songs themselves. They are honestly great, they didn't have boring sections, flow very nicely and have some moments of pleasant unexpectedness. The sound is great and mixed properly, and melodies are catchy in a chiptune-esc fashion. Can't really say anything too negative to be honest, but I would love to save these in some way like streaming or download.