Alright I finished all 80 stages, fighting through bugs and all, and it seems that one scene is missing/has a roundabout method of being unlocked that I haven't figured out (Heinrich's NTR scene with Emilia).
I'm kind of disappointed that a full two-thirds of the HCG is unlocked by completing the game to stage 50 (Which is, infuriatingly enough, only unlocked by resetting corruption to 0 and clearing stages 46-49 while keeping it that way). Everything after that is the new "lewd" variations of existing scenes and the final stage of the Heinrich NTR, but Emilia's one is missing anyways, or I'm just dumb and can't get it to unlock. The camp scenes are lacking (there's literally one) and it was kind of torture to play through at certain stages, it's not balanced at all (at the very least it was super easy to edit my stats)
