I've never given Spotify a try because of the crummy web/Electron player I saw everyone using. Wanted to try this out, but it only works with a premium account. That could've been mentioned more clearly, would've saved me the effort of compiling this thing.

I can't judge the main application but just the settings screen makes me feel like the UI library powering this isn't quite ready for prime time yet. I consider shortcuts and basic text handling like ctrl+a to select all text in a textbox to be basic features for any UI toolkit; the lack of such ease of use features really makes the GUI toolkit feel less native than the Electron cruft that's overtaking our desktops.

As for the legality, the DMCA sucks but this client is definitely in violation of it. Breaking the TOS isn't necessarily illegal so the tool is fine to use (at the risk of getting your account banned) but development can be quite risky. Hopefully, Spotify takes an interest and uses (a fork of) this project to write a faster player for their desktop clients instead of cease-and-desisting it to hell.