It's just been brought to my attention that the pre-order placeholder files feature of itch doesn't work as I thought it did and that nobody has been able to download the bonus music tracks or the quickstart gif. I'm trying to find out how to make this work, but for the meantime I've set the project to "released" so that you can grab these files.
This game still isn't released and orders are still pre-orders, but until I can figure this out the Buy button won't say pre-order.