All of the backgrounds were from asset packs from both here on itch.io and other websites. One of them, which has the backgrounds for the inside of the house, was I believe AI generated. I'd like to replace those with something that looks a bit better in the future but for now they work just fine.
Character art and CGs are AI with heavy editing. Process of rough sketch > fed to AI > prompt/gen tweaks > edited for errors and inconsistencies > resized and rendered for the game.