The game is missing important environment lighting, light beam from flash light (you play with a flash light over 90% of the game), reflections / shadows from light source, which is causing the game to look way darker. - Missing facial lighting (aka black face, there's no light source to brighten the characters)

• Flash light beam not throwing light at walls, plants, things in the environment
• Missing shadows due to missing light beam from flash light
• Roms, buildings, outdoor areas appear darker.
• Mirrors don't render the mirror effect
• Moving the brightness slider in-game doesn't affect brightness at all.
• Black/White moments when you take pictures of people appearing as ghost lacks brightness, rendering them darker.

This pretty much is an issue throughout the entire game.
I made a side-by-side comparison video, picking out some areas in the game where this is very noticeable and should be easy to work with.
The Wii U capture is raw input from the console captured through a capture card (Elgato HD60 Pro)
The Cemu capture is OBS, both recorded at 1080p, yet no scaling, color correction or such added.
No graphic packs where used to enhance the cemu capture.

I also made a set of saves leaving you at the spot shown in the video or close by, only leaving you to walk up to it.
The saves are from the european disc version. This game has some regional difference, afaik you can't use these on the japanese release and I'm unsure if they'll load with the eShop release of the game.

Link to video comparing the two (11mins, covers the basics and should give you an idea of what's going on):
https://mega.nz/file/UMkQCQyZ#u8Dc9Hl___sTJXXq1rdUp4Rpair1gN31UqMeFmMhPDo

Provided some screenshots from the video for a quick view.

If anything, contact me at discord:
chrissie#2000