well actually, I went back to the game and just listened to the music, I think the loop is long enough, it's just that it's not seamless, so this might be a godot/web/file import issue, what I did in another jam to """"""fix""""" this issue was to litteraly loop the song in a software like audacity and export the project with a big-ass music file that lasts like 10mn ahah
if you still think the loop is too short, I suggest adding music sequences with less instruments at the end/beginning of the loop or to switch up some notes for a little while and go back to the original melody and loop, it's not an easy thing ahah also what you can do is just make multiple songs and shuffle them but within the timeframe of a gamejam, if you're new to music, it might be hard to do !