This is an example of how to implement save slots in your GB Studio v3.0.3 game.

Features

3 save slots
Pause your game to save at any time
Delete your saves
View info about your game progress for each save slot

Notes

I wanted players to be able to save from a pause screen, but I didn't want their game to resume back into the pause screen. So in the code, saving is triggered from the pause screen, but you are taken back in to the main game and saving actually happens there. You could definitely refactor this code to have it run from interacting with a save point or something similar if you preferred though.
This example shows that you can have information about a particular save displayed on the load screen (in this instance has the player interacted with the cheese and/or the book). The variables I've used GotBook and GotCheese could both be renamed and potentially use flags rather than true or false states if you needed more flexibility. You could potentially use this functionality to display how many lives your character has, what items they've collected etc.
The code for this is pretty well tested but it was put together quickly, so it could definitely be optimised (give me a shout if you do).

Feel free to modify and use this in your game, commercial or otherwise. You do not need to credit me (but thanks if you do). I'd love to see your project if you use this.

I do not give permission to sell or redistribute this project file.

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