Tried the updated code. Still has same issues after the game completes with saving. Renpy fails to save on pickle, pickle can't handle the inner class design of this.
Viewing post in Shooting Game Plugin for Ren'Py (FPS) comments
https://seo-a-nam.itch.io/shooting-game-v1/devlog/820177/bug-fix-temporary-solut...
Hi! Sorry i checked the comment late. I suggest this solution for now, but i'll bring better patches on code in short i promise.