Press 's' to serialize the example values. Press 'c' to serialize custom values. Press 'd' to deserialize and say the values. Press 'v' to set your own the delimiters and escape characters. (press the green flag to reset them) This uses escape characters to allow for any values in the save code, which reduces the limitations of your saving abilities. If you want to use this in your own project then you can delete the 'when [...] key pressed' scripts and then backpack the 'Serializer' sprite and just drop it into your own project! To serialize, just set the 'Save code' variable to an empty value and then call the 'Write value (...) to save code' custom block for every value you want to add. To deserialize, just set the 'Save code' variable and run the 'Read value from save code' custom block to read out one value at a time (stored in the 'value' variable).
This was started when i looked at my older saving system (scratch.mit.edu/projects/849206855), but it is very different.