No, you don't need to have played StS - the only thing I really "borrowed" is the map with randomly connected battles and events.
I chose to leave the stats and mechanics a bit murky because I want the player to have something to figure out - but hopefully not inaccessible.
I understand where you are coming from with leaving some mechanics murky, but there is a difference between giving little information and making something that people can discover and understand inherently and giving no context to the core mechanics at all leaving people almost completely in the dark. Going back to StS it would be equivalent to that game not explaining any of its keywords on cards and you just have to play them and the hope is you figure out what it does.
In you game I can understand how some of the core stats affect me initially other parts I completely don't understand at all.
Charm and Passion I assume affect something to do with the girls bars and how quickly they fill, but I really don't know at all because it seems those bars are filled based on the difference between hand values when the hands are compared so maybe it takes a lesser amount to fill them?
Lucidity I see affects my starting HP, does it do anything else?
Psy power seems to affect the amount of psycards I get to chose from and start with at the start of the game but not sure if it does anything else. Does it affect the effectiveness of the psy cards? Also because I really don't know how the Charm, passion and luck stats work I also avoid the cards that provide a temp boost to those stats and go for slip and heal cards as I understand their effect and they seem to be more impactful during play.
Luck I can see affects my starting money, but I assume it must do something else as it can be temp boosted during the rounds but again I have no idea what it is doing.
BJ bonuses seem to happen after filling certain bars and give you bonus health and a bonus scene if you have a hand value of 21 or hit a 5 card charlie is that all there is to this mechanic?
The questions I have laid out here might be clear to you as you have developed the game but to someone else playing it its really just not understandable at all.
Also I have had json file decoding errors for events appear overlayed on one another when I get to the map screen, I never see the branching map (I think due to the event errors), when I win against a opponent I just chose another one, go back to the single node map and continue to play the game against another opponent. I also have had it often when winning or losing against my opponent that my mouse cursor disappears.