Do you actually get some decision making in this or does it stay like a psychedelic hentai?
It's got some scenes that need you to make the correct decision in order for them to be unlocked, but the narrative is more or less linear, yes. If you're having doubts about continuing and you're close to the start, I'd recommend sticking with it for a little while and seeing if it grows on you, it kind of changes atmosphere quite a bit after the first little arc.