Another idea is new game plus after beating the game normally you get to play again on a harder difficulty with the items you got but the game will be too easy so I'm thinking no knock back in new game plus but with no knock back the enemy's drop more health and ammunition and maybe possibly some variant of enemies like bloated fly that's filled with tiny flies once shot or infected fly or dog that have worms and stuff on them and if syahata gets bred by these creatures worms will be stuck in syahata making her be going into a give up state when an enemy is in range and the way to get rid of them is masturbation.