There are many areas in the game blocked off by cottages, preventing Trogdor from squishing the peasants on the other side. Fortunately, if you're playing the HTML5 version and encounter a vertical row of two or more cottages, odds are you can clip through them. Just line your feet up with the bottom of that ol' thatched roof, and keep holding the direction you want to go whilst mashing the up and down keys. That should hopefully get you through to the other side.