a better idea could have been to make the other girls driven by desire and have them wait in their rooms
so engineer waits in engineering the director would wait in her room
and if they see the player they will walk up and try to tempt/pin you down if the win they will prop you up on a near by table and call out to the monster to mate you which would stuff the mc's pussy making her slow walk as a punishment
his lair should maybe have the keys to the plane and to get the keys you need to sneak up to him while he is sleeping
another idea for the lair is to add a timer where you have a day time and night time cycle when the monster goes to sleep the girls all head to his lair to mate and help him rest
but at day time they all go back to critical areas that we need to get to and try to hunt us down
maybe theres a lust parasite he has that dont corrupt the girls mentally but it drives them mad with lust so the more mates they have the lower this pressure is this could explain why the director is driven completly out of her mind with lust to a point that shes willing to attack the other girls