You must save your games if you want to re-open them again later.
When you first use Scratch on a computer, you should make a folder in which to save your games.
You should create a folder the first time you save a game.
Complete these steps ..
1. Go to "File > Save to your computer" ..
2. Click on the new folder button and name the new folder. Use your name (eg "Nathan Watts") ..
.. then click "OK" or "Create".
3. Next, find your the folder you have created and click to select or open it.
Important!! You must OPEN your folder before saving your game.
4. Click on the filename and type a name for your game.
If you are using a Mac DO NOT forget to add ".sb3" to the file name..
6. From now on, you can save your games in this folder. Just make sure you double click to open the folder before naming and saving your game.
To open a saved game, complete these steps ..
1. Go to "File > Load from your computer" ..
2. Find the folder that your game is saved in and then double-click it to open it ..