It was Chrome and Windows, but I have tried again and it works now, weird.
It's true that the sound adds to the game and the music is great, although I feel that the sound balance could be improved. Specifically there are some sounds that are louder than they should imo, for instance the sounds when hitting an enemy or when the player is hit. I feel that the downloadable version sound is even more unbalanced, but that may just be not true and only my impression.
Indeed that's odd. I'll try to look into it, but honestly not sure how.
The sound of being hit or hitting are important, so they are intentionally louder, but of course it might be too much. And the sound balance can absolutely be different between platforms - I didn't really notice it in this game, but when I was exporting https://ralh.itch.io/fastest-gun-in-the-west to Android there were massive differences, some decently loud sounds were suddenly completely silent. I had to explicitly set the volume of every sound per platform. And of course this only happens in the final build, so it's really annoying to test.
