title: What is the best way to save and load variables?
body: <p>I have a bunch of variables like "Upgrades bought", "Amount of money" etc.
  I want the most efficient way to save these variables and load them upon starting the game, as you never even exited the game (every single thing stays the same).
  So, all the settings and variables stay the same, until you reset the game.</p>
  
  <p>I am asking since I think this is a huge and really important part and I want to begin with the best technique.</p>
  
  <p>What are your suggestions and how can I implement that in my game?</p>