Euphoria (yes, without capital E) is an immersive, deep, philosophical, multilayered virtual novel (VN). It's also a rape of the soul, etching its horrors into the poor reader by a too-good convincing personalities and voice acting, transferring the full power of the horrific story like a sledgehammer.
This goes lightyears beyond the different fetish included. As if having executions, rape, torture, coprophilia, incest - all these is minor in face of the heavy atmosphere and burning pain felt by any sane reader. Do not look for sexual excitement here, this is not what the creators had in mind.
Without any spoilers:
The novel has different routes, accesible by choosing the girl 5 times in a row, one route for each unique girl. All routes enrich considerably the True Route (Kanae's).
No matter what route you take, the main character (Keiuske) is torn in front of the horrible acts he must follow. He has a dark, sadistic side - but he does not accept this, seeing how wrong this is. However, the plot enforces him to enact his dark desires, bringing him ever closer to a breaking point where he will lose his identity and will become a monster.
The other main characters are each unique in personality and behavior.
The game has some major twists, most of which caught me off-guard.
So - take your pick. Be forewarned, It is VERY disturbing and hard to bear. I may even say I survived it. On the other hand - it is an excellent VN. Make your own choice. Personally - if I would have known, I would have avoided, not because it's bad, but because it's too good.