Slight story spoilers I guess?



It's really not that bad. The 'nightmare' aspect is mostly just the constant meaty visuals. The MC sees everything as made of gross meaty viscera and the purpose of Say is that she's the only thing that's NOT creepy to him while in reality to anyone that's not him she's probably a creepy meat monster. They never actually show Saya's true form and while there are chunks of flesh in a fridge at one point I don't remember there being any actual on screen violence or gore. There's some non-con and stuff but it's honestly really average as far as the 'fucked up' shit it explores.
That said I still enjoy the game. I haven't read the manga though, didn't know there was one!