From page 1:
"The short version: don't target one resolution
A common misconception is that you need to target a specific resolution, like 1280x720. However, there are so many different resolutions used that it's ridiculous to pick just one. It's much better to pick an aspect ratio, then scale the game to fit that. For example, instead of 1280x720, target the 16:9 aspect ratio. (Just enter any 16:9 resolution for the window size in Project Properties.) Enable Letterbox scale in the Fullscreen-in-browser project property, and now your game should appear correctly on any 16:9 resolution."
From what I understand, if you want your game to appear on a 16:9 (or in my case 4:3 ratio) you HAVE TO pick the "SD 16:9 project" or "SD 4:3 project" when first selecting your project before inserting even the first object or event. There doesn't seem to be a way to do that. The Project Properties thingie only allows me to TYPE IN my desired resolution.
Am I misunderstanding this tutorial?