Thanks for playing even though we have this issue!
We updated the game yesterday night to fix bugs, edit the levels etc *and* made a WebGL export (It was a download game before)
Unity has some issues right now with videos in WebGL games, so we sadly lost our cool intro, outro and credits scenes, which is why you can't see them and can't know how to start the game :/
But we're already trying to find a workaround and will publish an update as soon as it finally works!