I think we should have moods and more stats for the pets.Like the mood is affected by their stats in certain things.We already have hunger.So, how about these?
Fun: They need to be entertained to keep their mood up.I mean you wouldn'y be very happy if I was bored all the time.
Energy: They need sleep to replenish this and you can choose how long they sleep for.The more energy the more they can play and exercise.Food can replenish energy a little bit.
Hygiene: How clean the pets are.If they are grubby and dirty, they won't be in a very good mood.Things like soap, and towels can replenish this.
Sick?: If the pet is sick this will tell you how sick they are,and what they need to feel better.If they need more rest it will say so.It will also say if they need toys or anything else.
Mood: Basically stating if they are happy,mad,or sad etc,etc.
This is all for now.I'm not sure if this was suggested before but this will require users of Res to spend more tu since it's already way to easy to gain and the value of tu is going down.