Managed to "satisfy" girls during orgy scene and get Kyoko's ending. The game explains mini-games quite poorly: during first game you have to release mouse before circle becomes red (as soon as it's fully filled) and watch their faces, during filling, if you see them angry, release immediately and try other part. Plus, in the last mini-game with the girl from the tube, you also have to press glowing screen located to the left of girl (of course the game doesn't say that, Rita just says to press buttons as they start glowing).
The advantages of existence of mini-games in porn games is very questionable at first, but making them quite difficult, demanding and non-skippable? Very strange decision. Why I can't skip orgy scene? I can't even fuck it up to end it earlier, which is a problem if I would want to play again for another girl. But the real problem for me, personally, is the absence of dialogs during sex scenes. You just watch two people fucking, the MC doesn't say anything, but I don't care about him, the girl is silent - that's the problem, what is the point of making several girls with different personalities if all sex scenes (I actually haven't seen them all, only Kyoko's and Rita's and I'm hoping that I'm wrong, but something tells me that I'm not) are just gifs with pointless mini-games?
P.S. What is the actual point of satisfying girl during sex scene? You won't get ending, unless you do it?