In the previous demo version, some players experienced the game freezing when loading the tutorial beat map. This is due to the beat map data files use decimal point in float numbers. When running on a system with date / number format that uses decimal comma (for example, most European countries), the data files will failed parsing, causing the game freeze.
It took me quite a while to figure out the problem (thanks to the friendly discord user ouchinikaeritai in our channel). The bug has been fixed and the new demo build is now online.