This game in its current state is deeply perplexing to me. This is gonna be a long one so bear with me please.
The story Concept: A lot of Wasted Potential
It's a futanari neatorare centered experience (unfortunately) with a decent idea but kind of badly executed. I should probably mention the fact that I'm likely not the target audience here, as I do not enjoy neatorare or referred as NTR from this point on. I can understand the fantasy of stealing someone's partner, but getting cheated on AND getting off to that just doesn't resonate with me. I've only tried to play this game because I enjoy futanari, only to find out that this game contains cuck content for the lack of a better term.
The Fusing Body plot-point: It could have been more...
Interesting idea, dragged down by the potential of what could have been. I strongly believe that had the main character not existed, or been the other half of the fused body would have both explained the genitalia, and avoided the issue of NTR altogether.
The gameplay: You Know the Drill.
...It's non-existent. Not that I expected much really, it's just the usual RPG maker-style game with pixel sprites. That's not inherently a bad thing really, but combat is really not the focus. You mainly go around triggering NTR events, being able to choose if the character you play as is aware or not about the fact he's getting screwed over.
The writing of the characters: I wished for something better.
It's simply not compelling, neither is the story presented to me. This could also be a result of me already not being on board with what the game was trying to offer, but I was baited into thinking this was just a futa game and likely so were you! To those thinking 'It's just a porn game bro'', at the end of the day it's a story driven game that has a narrative to tell. Having a mediocre story and justifying that due to its NSFW nature is insane to me since there's plenty of genuinely good experiences. Hero Harem Guild, while not containing any futanari content is a pornographic game on this very same website that has managed to make me both interested in the story of the main character, and even more importantly, the women you're interacting with. The point is, it's okay to expect and want more.
The 3D sex scenes: Yeah, they're really, really good.
In a vaccum, the futanari sex scenes are honestly really amazing. Too bad the NTR context ruins it completely. Even so, I don't really recommend going through this to get to them.
Overall thoughts:
The game looks to be abandoned due to internal troubles of the developer and their community. Their patreon page is down and Kemono party's last archived post was months and months ago. It's safe to say there will be no more updates anymore. I do believe there is a lot of promise in the idea of fusing bodies into a futanari, but it will probably not be realized.
To the dev behind the game, ultimately you should make the game you want, even if I really don't like what you're going for. This long ass review was made because I really wanted to like this project but I just couldn't. I overall wouldn't recommend trying the game out, I haven't mentioned it already but the 0.30 build has plenty of game breaking bugs that have forced me to close the game on multiple occasions.