Oh no ... brotli / gzip compression strikes again. (https://itch.io/post/1985533 and https://foxxthom.medium.com/unity-2020-webgl-freezing-at-90-357e1346aec6 have some info on what you're encountering, just set compression format to none)
Either way great game! (Edit: currently the way the download is provided breaks jam rules ... is there any way you could have (before the jam ended) uploaded a downloadable to itch instead of linking to another file ... ?)