Okay, I haven't played, near as I can tell the previous game. However, this game, I have. And I do have a few things that can be added later on. What I mean is added onto the game in later versions. Before I get to the list, it is a good game, so far. I like most of the content, and it is an interesting concept.
1) Money. I would like to be able to find/make more money down the road. Say selling biomatter to the University, after Izumi is back there to work. Maybe something else can be sold, later on.
2) Milking. This is a good mechanic, but I would like to see a reduction in energy option in bio to mass milking. The individual can be still 5 each. But something to reduce the milking en mass can be useful.
3) To reduce suspicion, and taking the girls initially, they can be seen on the beach, or at home, after a few days. They can go back home, work, etc., after being seen. They can make it back in the evening, etc. over night, then "released" during the day.
4) A plausible excuse as to why you spend money at the hardware store. Such as trying to build a shower for coming off the beach, a dock that you can lay on when you are swimming. Something like that. This way, while the hardware store owner may still call, it might take a while.
These aren't complaints against the game. Just some things somethings maybe someone hasn't thought of yet, or otherwise. Only complaint I have is no walkthrough on things. But that is something that can be worked on down the road.