For those who don't know how to save their game :
You go to the settings wheel at the top right, then scroll all the way to the bottom of the window and you’ll be able to press the blue button that gives you a save code. You can either copy it or download it as a file. When you want to play again, you just need to restart the game and do the same steps, but this time press the green button. Depending on whether you copied the code or downloaded the file, you’ll either need to paste the code or click “Upload txt”, and then you’ll be able to load your save.