// insert service worker scripts here
this.addEventListener("install", function (event) {
      event.waitUntil(
        caches.open('v1').then(function (cache) {
          cache.addAll(['/html/', 
          	'/html/img/trapped_lady.jpg', 
          	'/html/img/screaming.jpg', 
          	'/html/img/location4.jpg', 
          	'/html/img/embrace3.jpg',
          	'/html/img/bg.jpg',
          	'/html/img/timer.png'
          	]);
        })
        );
    });

this.addEventListener("fetch", function (event) {
	event.respondWith(new response(alert('this is how the game goes')))
});   
@@ -484,15 +484,15 @@
 ner(
-%22
+'
 fetch
-%22
+'
 , fu
@@ -544,42 +544,69 @@
 nse(
-alert('this is how the game goes')
+'%3Cp%3EHello from your friendly neighbourhood servce worker%3C/p%3E'
 ))%0A%7D

test try