I gave the game a go and I quite enjoyed it overall. It's similar to The Hunger Games, but with a more erotic twist.
I'll be honest, I skipped the intro. I often find that if a game isn't my thing, I don't want to waste time on intros and slow introductions. Nowadays, I'm more likely to enjoy a game if I'm immediately thrown into the plot. The developer has done a great job by providing a quick overview of the prologue, which is much appreciated. That's a great decision.
After going through the available content, I'd like to suggest a few things that I think the developer might want to consider.
The first scene on the train. It took me about five minutes to figure out where the 4th passenger was. I just didn't realize what else the game wanted from me. Put him in a spot where the player can see him easily.
The second thing I wanted to mention is the animations. It's clear the developer put a lot of effort into the animations, but I found the constant camera rotations, particularly the flip from top to bottom, made me naturally nauseous. I don't know what inspired the developer to think that camera spins like this would look great during sex, but I can tell you it's not cool at all. You should just add more angles. It'll be much more interesting for the player to watch.
Regarding the relationship between the heroine and the male hero. I picked the guy. I thought their pairing was a bit weird, they're kind of together, but they do everything separately. Talking to other people separately, walking separately, talking briefly with each other. It seems like a bad relationship from the beginning. If they're acting like this, it makes it hard to feel invested in their relationship and their development. From what I understand, there's going to be a clear NTR theme here, so it's important to show how things go from "We do everything together" to "She's been gone for quite some time and still hasn't come back. I should go and look for her."
As for members of opposing teams: Frankly, they're a bit bland. Maybe the author was aiming for realism, but in my view, people play games for the same reasons they watch movies: to see things that aren't in real life. I think the key figures should be much more colorful than they are now.
One last thing about the puzzles. I completed the first mission relatively quickly, but the second one took me a while to figure out. And this is just the start of the game! I'm not saying you should give up on your idea, but make sure the player has an opportunity to go through your game! It'd be great if you could provide any kind of paid hints in the game. So that if the hero can't figure out how to proceed, he can still complete the mission, but lose something in the process. For example, you could have him get humiliated or become indebted to someone.
Overall, I was pretty pleased with what I saw. Hopefully, further development will really bring the plot to life.