Autosave is finally here! Now you can build your game without having to worry about saving continuously.
If you leave the page before explicitly pressing the "Finish" button (renamed from "Save"), your unfinished game will be available in your drafts.
Any draft games you have will appear when you navigate to the game builder to create a new game, where you can click on a draft to load it in and continue working on it. You can also delete drafts by clicking on the red trash icon.
The save status of your game is shown at the top above the tabs: