I love this :) Thanks very much for making it, it's elegantly designed.

Since you asked for feedback: in terms of usability, I found the 'seek next' and 'seek previous' buttons confusing, since they're positioned left/right but control motion up/down, and even switch their direction based on loop. (This is because "forward" and "back" also change based on loop -- an indicator for that would help.) Adding navigation via mouse wheel would be perfect here too.

Sorry to ask for even more, but I'd personally love to see door opening / door closing sounds added (along with 'ドアが閉まります' and the alarm) to fully round out the soundscape.

Don't mean to be too picky! -- it's very enjoyable as is.

Adding to this, it would be amazing if the background noise will be louder when the door is open together with the sound on that station.