The art style and character design are peak, but it would be even better if H-scenes could have more stages like in "Goddesses' Whim" Additionally, I feel that the early story might be progressing too quickly—for example, the exploration of new dimensions and the development of relationships with girls feel a bit abrupt. The transition from the earlier tasks to the university part also seems a little jarring. Overall, it's a fantastic game so far, and I'm looking forward to future updates!
I haven't personally played Goddess' Whim, so I don't really know what they are like. There's typically two stages to each animation though isn't there? The most recent Steph sidequest had 4 animations in the one scene. Maybe not so much in the early game. Most of the early game is paced quite poorly because I was still getting used to writing in this format, I'm well aware that characters like Azalea are really fast paced at first, I've only been slowing them down recently. The University stuff was intentionally jarring though, mainly to give the Prime dimension more purpose in the story, but also because behind the scenes there's some spoilery stuff happening that requires that to happen. It also opens up the ability to have more character interactions that don't involve the MC, which is a common pitfall that these types of games fall into that I don't want to follow.
And to answer the question in your reply, no Sidney will most likely just share events with Valentina in the future. She might get a large sidequest, similar to Steph in the future though.