I've played to the end of 0.19 and played a ton of 0.18, and my thoughts...
If Chapter 4 is from the time Vera receives the drug on Friday to the takeover of the chemical plant
and Chapter 5 is from that point on..
The Chapter 4 seems more a sandbox and Ch 5 seems to be clicking the same 2-3 buttons over and over again.
That's not to say the game does not have a lot of promise, it has a ton of promise. If it can fulfill most/all of its hinted functionality, then it has a possibility of being one of these cult games that picks up some mainstream critical love..
Would love to see more body models implemented, but it would be nice if they can be reversed. bimbo -> strong -> ideal, etc. But this only makes sense if the body models become a part of the scenes. And yes, I know how exponentially exhausting that is to the developers of scenes.
Would like to see more post-conquest content. You should be able to do things with Erika, for example, after she is under your control. Maybe she doesn't become an agent, but sex scenes on demand? Yes!
Would like to date Emma post body mod.
Supplies now limit what damage a player can do. Perhaps rolling into "Ch 6", Luka's supply purchases and limits can be expanded. I'd hate to have the day to day for the MC being fetching supplies. I was consuming 95 supplies/day after readjusting for Chapter 5.
Once you're in Ch 4 and you have an economy established, then Dimitria becomes the least accessible of the agents. That means she doesn't get developed as much. The other three are easy to "max", give them every training of every kind. Perhaps the Date interface for Dimitria can access Tasks, or other things to do with her?
I'll note that there is kind of a disconnect for a player as he moves from fully blown agent style characters to the more limited roles folks like Margaret and Erika play. It leaves you with a feeling your fun is being set aside for plot development. The driving force, more or less, from the beginning to the middle of Ch 4 is fully fleshing out what your agents can do, and without more agents, or agent like characters, that motivation dries up.