Oh, sorry about that! The save location should have been set to $HOME/Library/RenPy/TODO-today but as it looks it wasn't found in your case. Have you had any trouble running other Ren'Py games?
Solved it -- just downloaded it straight from the site, added to my usual Applications folder and opened the app directly rather than using the itch.io app :) Now it not only works, it also brought back the saves from my previous playthrough from part one too ^_^ But I guess it's a heads up in case other people have the same issue, hehe.