Hello there,
I would like to say first that this is quite an awesome game and I liked it. Hope you guys will make more similar things.
About bugs, I would like to say that I found around 3/4 bugs (or just 3 if u put 2 bugs together) where:
1) There's indeed a bug with spacebar skipping some dialogues and if at some it's the one before last dialogue and you have a character on the screen, the character remains and doesn't disappear.
2) Another problem is in the onseen part (better view for yourself rather than explain):
Shortly: either this is an error from idk what I Did earlier by spamming spacebar sometimes or just the game itself but you can see some layers overlapping and missing and well... not looking great overall + I think this scene (animation) is also played too early when chiho and ryunosuke were actually just standing in front of shota naked (assuming they were not having sex beforehand but the text doesn't tell us anything like that).
3) In the Balcony H event, when you finish all 3 times, there is another chance for the sweet spot to hit where the slider was last time and when your screen goes black, you can't do anything unless u were still holding the slider to move it if you catch the arousal bar filling again. It's not annoying trying to complete the event 3 times but it's annoying when you have to be careful after to not get busted while having a black screen.
a somewhat minor bug: sometimes the voice over is being played either early than the current text appears or later (for example, the voice over was talking about future text in the first part where you have sex with lilith for the first time.)
As for what I did during onseen scene, I've only played the minigames with chiho's view (seen in Dragoon's guide that shota's view are bugged and made u not end on day 10+ and had to do multiple reruns etc so I focused on finishing this first and then take a look at them later), I've rewinded once to see how it works, not sure if I was in day 2-3 but around there.
Hope I provided some info on these bugs. I'll try to do the onseen again and hope that it will be fixed.