Save Gamestate - Not only 1 variable

How can i save the whole game without a million function. I made a game where you can build and i dont know how to save the whole game. How can i make this if the player builds 1000 blocks?

Storage is your friend you can save almost anything in Storage with a few lines then load on demand

Save the first play time, the player sword, the game level, and so on…
The just Read the value you need from Storage “game_data” and assign to a variable.