This game is quite difficult and requires a deep understanding of the map generation rules. Every heart cannot be wasted, it must be replaced with an upgrade point. I have almost deduced the entire map. But there is also a little bit of luck involved in the middle.
I also encountered this problem, and later I discovered that it was a browser restriction that did not allow direct loading of resources and JavaScript scripts from local files.
My method is to run "python - m http. server 8000" in the game file directory on the console (Python needs to be installed in advance), and then access this URL in the browser: http://localhost:8000/index.html
