You tagged this as a downloadable executable for Windows, Linux, and macOS, but it is not any of these things. Change the game type from “Downloadable” to “HTML” and select the box that says “This file will be played in the browser.” (Also, it’s brotli compressed. That causes problems, so might as well go into the player settings in Unity and set that to Gzip or Disabled instead)
EDIT: fixed, thanks! Now that the game is playable, I am confused as to what the goal is.