If your menus still need a creepy coat of paint, these are free:
- Horror UI Kit Lite: 19 pixel art pieces: rusted panel, dialogue box, blood buttons, toggle, checkbox, hearts, skull, cursor and a health bar.
https://willosuna.itch.io/horror-ui-kit-lite - Horror UI SFX Lite: 30 dark interface sounds, one for every event (click, confirm, error, open, close, alert...).
https://willosuna.itch.io/horror-ui-sfx-lite - Essential UI SFX: 150 neutral UI sounds, 5 versions of each event so nothing repeats.
https://willosuna.itch.io/essential-ui-sfx - Pixel Cursors & Icons: 121 pixel cursors and icons (skull, key, potion, lock, chest...).
https://willosuna.itch.io/pixel-cursors-icons
Sounds come as WAV + OGG, graphics as transparent PNG at x1 and x4.
I made all of these myself, drawn and synthesized from code: no third-party art or samples. Free for commercial use.
Good luck with the jam, can't wait to get scared!