If you're not using the Itch app (which we recommend!) you'll have to manage your own save data between updates. Here's how to move your save data around.
Your save data is inside the TumbleSeed.app package. Right click on the app and choose "Show Package Contents". Open the Contents folder. Your save file is the called TumbleSeed.ts. Copy it to the same place in the new version of TumbleSeed that you downloaded.
Find where TumbleSeed is stored. Open the TumbleSeed_Data folder. Your save file is TumbleSeed.ts. Copy that file into the same location wherever the newer copy of TumbleSeed is.
Clearing Save Data:
If you're using version 0.45a or later, press ctrl+` (left control and tilde). This will clear your save data and start you over at the beginning of the game. This is useful if you'd like to test out new features like Quests, or if you'd like to have a friend play through the tutorial. If you're playing a version prior to 0.45a, you can delete your save file at the location detailed above to clear your save.