The first thing that hits you is how this isn't trying to be anything other than what it is. Another one from the F-Series, and they've picked Rei this time. Not that I'm complaining. The whole interface is just her standing there in a white bikini that's barely doing its job, and you've got these buttons on the sides. Click. New position. Click. Different angle. It's almost too simple but sometimes that's exactly what you need when you're not trying to solve puzzles or read walls of text.
I spent way too long on the missionary variant where her legs do that thing. You know the one. The cumshot mechanics are straightforward, no weird timing minigames or anything, just build it up and let it go wherever the current pose allows. Some positions give you better angles for the finale than others, and I found myself cycling through them way faster than necessary just to see the differences. The POV perspective makes it feel more immediate than a lot of other browser games I've messed with. Less like directing a scene and more like being in it, which is probably the whole point.
The bikini stays on the whole time. Not sure if that's a feature or a limitation but it works for the character. Very on-brand for Rei specifically. I kept wishing there was a way to remove it completely but then again the tease factor does something. The whole thing is deliberately unpolished in that specific F-Series way where the jank becomes part of the appeal. Like finding old doujins on a forgotten corner of the internet. My screenshot folder is an absolute disaster now and I'm not even going to pretend I'll organize it later.