A little bit (or a lot) of save system refactoring later and now I have multi save slot support!
Here's a quick gif showing two different saves being loaded and then starting a new game. The title screen and menus are just placeholders so I could get something working:
This was something I wish I'd done in Resonant Tale, but it would have been a big change to make late on so I declared it out of scope. It's definitely more complex, but the premise is pretty simple - it basically just requires some methodical shuffling around of lots of variables!
The crux of my approach is to have a slot variable for the currently active save slot and to call events to save and load specific to each slot.
Saving now looks (pretty much) something like this:
on save do
call "saveS{slot}"
end
on saveS1 do
s1_player_level = player_level
// etc.
store "s1_player_level"
// etc.
store
end
Loading is similarly like this:
on loadSlot do
call "loadS{slot}"
end
on loadS1 do
player_level = s1_player_level
// etc.
end
While deleting a save (when starting a new game in that slot) looks like this:
on deleteS1 do
toss "s1_player_level"
// etc.
end
Once you factor in all of the variables in the save data and the multiple save slots, that's a fair amount of repetitive and duplicated code, but it should be easy to manage going forwards.