Maybe have the first companion be customizable, making them feel more personal. Like selecting their body type, hair, name and picking from a list of how they might relate to you, like childhood friend, sibling, neighbor etc. Doesn't have to replace the tutorial companion either, they could show up later.
Speaking of that customization getting to buy and equip sexy cloths on your character and theirs. Also a place where you can go to change outfits buy them and change hairstyles and appearances but not races.
Being able to romance them and other npcs like the bee girl after the spider attack
Also being able to turn the table on the spider girl with a strength check or luck, to have her be on the submissive side could be a nice touch.
When too many bodies and items pile up it'd be nice not to be kicked out of that observation menu or have a pick up all or take all items on floor option. Different weapons having different auto attacks, for example if you get an axe the auto attack is spammed less frequently but deals lots of single target damage, a hammer would have a chance to stun an enemy, potions or throwables could make the enemy sleepy or lustful leading to spicy scenes. And swords could have that fast auto spam the way the auto attack is currently