I put this off for a really long while, like half a year. Then, I finally picked it up two weeks ago. This is definitely a feel good AVN. There's a lot of time dedicated to flashbacks to show the contrast of better times in contrast to how the main cast copes with the apocalypse in the "now". Personally, I found the only real main cast to be the MC, Carol, and Naomi. They have the most fleshed out personalities and time spent on screen.
EDIT: Did my second playthrough after a year. The game has many scenes that elaborate on other characters' perspectives and provide proper subtext for their actions. I think the 2nd playthrough is worthy of a bumping the score up quite a bit. Although, I do find that many characters still suffer from a proper amount of development, it's nothing new when it comes to creating a big harem in a visual novel.
The sounds/music is alright, they suit the tone of the story. The visuals are just okay, if you're looking for something insanely sexy, you might be able to get your rocks off, but these models are somewhat old. There are lots of dialogue/choices that change how characters perceive you and affect future chapters. (For example, depending on how affectionate you are to certain characters, they're either absent or present in the final act of the game).
The main girls, for me, were Carol and Naomi. Sydney as well. The three characters you're introduced to the earliest. Everyone else doesn't have enough time dedicated to them or their story moments were spread thin. You also have the most H-scenes with them.
The dialogue/story is okay. You're a dad trying to keep the people he loves alive - be it your adoptive daughter, her best friend, or some other people you meet. I love the flashback moments and you get a lot of these early on. However, the game uses them less and less in the 2nd and 3rd acts of the VN. For me, these were the stronger points of the game, they're also why Carol and Naomi are the best LIs to me. They have the most history with the main character and it's pretty interesting and fun to see how their dynamic was in the past.
Edit: I've said it previously but the game feels like 2 different games. In the early chapters (up until chapter 16ish), the game feels like it has a proper post-apocalyptic setting. Act 1 and 2 are excellent and maintain a fair amount of tension while still keeping things nostalgia-coated. I like the "then" scenes sprinkled throughout to really rub in how different things are from the cast's past lives. Act 3 falls off dramatically because it becomes a "fuck festival" for lack of a better term. The MC spends much of his time inside girls and less time properly speaking or spending quality time with them. I hate that the most, because I think relationships shouldn't just be sex and more sex. The things that make relationships feel sweet and romantic are the regular trivial moments and I think because of the number of relationships he has, MC can only do two things: surviving and fucking. I feel the most pity for Carol, because all of the development they do for her ends up feeling a bit wasted near the end. They don't continue developing her, just making her the queen of the kingdom and kind of calling it a day. But considering the length of the VN, that cannot be helped and I don't blame the dev for wrapping things up the way they did.
Overall, 4.5 out of 5. I took half a point away since the story starts to stagnate in the last 3rd of the game - too many characters to flesh out/ revolve romance system around.