Most of the people are fine playing the demo on the site proper, but someone might find a use for this (as I did). Here is a quick'n'dirty javascript-bookmarklet that opens the Escape Goat Demo url in a 2x scale window of the game. (736x448)

javascript:(function()%7BgoatWindow%20%3D%20window.open(%22http%3A%2F%2Fplayescapegoat.com%2F%22%2C%20%22Escape%20Goat%20Demo%22%2C%20%22toolbar%3Dno%2Cwidth%3D736%2Cheight%3D448%22)%7D)()

Just copy that to newly created bookmarks URL/address bar, and after it you can just click select the bookmark and the demo opens.