Instead of using the system's in-built save function, you could use LocalStorage and a Dictionary. Local Storage can hold values for you between play sessions, and the Dictionary will allow you to store multiple values in one.
First you'll have to add both LocalStorage and a Dictionary to your game. When you want to save the game, first clear the dictionary using [ Dictionary > Clear ]. For each of the variables you want to store, use [ Dictionary > Add Key ] to add a key whose name is the name of the variable, and whose value is the contents of that variable. Then, use [ LocalStorage > Set item ] to have the event create a new LocalStorage value. Make the contents of that value Dictionary.AsJSON. This will store the whole data structure of the Dictionary under that value. Name the value "savefile" or whatever. That's your whole save action complete:
[ Dictionary > Clear ]
[ Dictionary > Add key } ( variablename , variablevalue )
[ LocalStorage > Set item } ( savename , dictionary.asjson ) <<< Repeat for each variable
Fortunately loading is a lot simpler. When you want to load a save file, first you must check it exists. Use
[ LocalStorage > Check item exists ] and enter the name you gave your save - "savefile" in my example. You must then use the trigger [ LocalStorage > On item exists ] , and the action [ LocalStorage > Get item ] - again, giving the name of the save. Finally, [LocalStorage > On item get ] use the action [ Dictionary > Load ] giving the value LocalStorage.LastData to send the Dictionary structure stored in the LocalStorage value back over to the Dictionary. Finally, set each variable to the stored value using [ System > Set variable ] to Dictionary.Get( "variablename" ).
- - - >[ LocalStorage > Check item exists } ( savefile )
[ LocalStorage > On item exists } ( savefile )
| - > [ LocalStorage > Get item } ( savefile )
[ LocalStorage > On item get } ( savefile )
| - > [ Dictionary > Load } ( LocalStorage.LastData )
| - >
[ System > Set variable ] ( Dictionary.Get( variablename ) <<< Repeat for each variable
Good luck! This should be a fairly robust system. You can also download the Dictionary.AsJSON to make the save files portable, and you can save multiple save files by simply changing the name of the LocalStorage value for each new file, whilst still retaining the integrity of the file itself. You can also debug save files using this method a lot easier, so if your users have a problem you can easily establish a system to allow them to send a save file for investigation, and it should be easily loaded at the other end.