Just played the latest update. Figured I'd give my two cents on it and some of the topics of discussion.
First, the update itself:
Great. Loved all of the content, loved the interactions between Kara and Lola, and am glad to see some experimentation with mechanics (e.g. branching paths). My only complaint? I just wish there had been more in this update! Keep up the good work, guys.
Now, onto the issue of branching story mechanics. The issues with a branching storyline in Ren'py center around three issues:
1. Saves and replays
2. Making the choices consequential short-term and long-term
3. Content locking
The first problem is straight forward: the Ren'py save system does allow you to easily access crucial flashpoints. For example, I saved before I chose to gave Lola one of the serums. This makes accessing those flashpoints during replaying the game much easier, and thus makes it easier to replay a game and get different scenes and endings. The problem is that the more branching paths makes it much harder to organize and track saves. Right now, I have the top row of the save slots for the Green serum path, and the bottom row for the Pink serum path. But what happens when more branching occurs? Things start to get messy.
The second issues is that a choice should serve some purpose beyond giving access to certain scenes (unless it's the player choosing to opt out of scenes featuring content or a fetish the player dislikes). I'm not sure how the different paths will affect the player's growing harem yet, but keep that in mind when you continue story development. Make these decisions count, or, if that's not the goal, make it possible to backtrack in some way shape or form (I'm not advocating for time travel, but the reversion serum some have suggested is a good idea).
Thirdly, these branching choices tend to lock the player out of content, when the player would prefer to access as much content as humanly possible. This is a porn game, not Bioshock. Replays are harder to justify, I'm afraid. A good example of how to do content locking badly is Dreams of Desire, where a decision in Day 3, 4, or 5 (I can't remember which) suddenly locked players into a restricted set of endings when most players considered the decision to be a minor one while playing, and wanted to access the locked endings. Thus far, we only have two branching paths, and they are a later decision (I advise training Chrystal, Kara, Harley, and Yuki before doing anything with Lola), so fortunately we're still in a good place.
What's the solution? I'm not sure, but the reversion serum is a good idea. Another idea someone mentioned was having the player choice center around which serum to administer first (i.e. choose the pink serum first and use the green one later, or choose the green serum first and use the pink serum later). I'm just throwing out food for thought.
Another thing I wanted to throw out is storyline: so far, we know the Professor has used the serum on himself and the girls. His intention was to test the effects of the serum, and it's been smooth sailing with little repercussions. The devs have been hinting at consequences or danger, and I hope to see a bit more of an overarching plot as development continues. There's a lot of different avenues to take this (an attractive rival professor, a stuck up policewoman, or Lola's mother, as possible future antagonists/targets), and I hope you guys work your magic with the same skill and success as you have up until this point.
That's enough out of me. Thank you for reading, and keep up the good work, devs!