Can you make the characters a more lively? (for example) If you put a plant in a room, some characters will water it in real time, and then he will go about his business - walk around the room, sleep, scratch himself etc. And other interactive furniture (TV, aquarium, chairs, globe аnd other).
Such an idea: add a big hot pixel art of the original character, after reaching 100% of the relationship. You can also save the gender in these arts, this is a reference to the main idea and concept of the character.
