I think its fair to say, for Alleys of Purple mist, when will we see any purple mist involved? If anything this game is pretty similar to another game called "Predation" by hornedlizardstudios. They have a purple mist system similar to this game only if you're ever in the smoke it's an instant loss.
I might also have another idea in mind although small.
A safe area for the player to potentially have collectibles that can be obtained and rewards for them. Could be anything you think could reward the player for their time. Also various challenges which can unlock outfits.
Maybe a police station area, apartment, or if you can't do that just have a menu if the "safe area" thing doesn't work out.
Conditions:
Conditions, Allow the player to suffer or benefit from conditions, like if the player is stripped then you get "Exposure" which will mean damage against health from NPCs will now also affect the purple bar although rudimentary at the moment and you can probably understand why.
Challenges:
A challenge could be like performing a dare with certain weapon restrictions or similar conditions, have the map itself modified to make the challenges more difficult, if the challenges were done they'd reward the player with whatever they're looking for like outfits or medals like gold, silver or bronze, or both.
An example of a challenge would be (insert challenge name), for this challenge, the player is stripped, and their purple bar is almost at max and they would have to avoid getting hit for the rounds, or escape. If they get hit well its an instant loss and they are bred, they are also ovulating.
If a player doesn't enjoy the "lose to get H scene" then I'd say allow for those kinds of players to beat a level of the game or eliminate an enemy to gain an H scene for them to view later, there is the matter of certain enemies being more difficult than others so maybe a bigger enemy type would need different requirements.
How I see it working would be a currency for the game used to unlock the H scenes, they would unlock depending on specific challenges and rating. Bronze would give you x amount of said currency, Silver would get you more of the currency + H scene or another reward. Gold would be the best rewards you can offer.
Final:
Let me know what you think. It's fine if there are some things here that can't be done but it could give you some insight.