Personality should be the main focus of this game.

Extra trait slots, aspirations that matter (sims 3 and 2 aspirations were great), wants & fears, likes & dislikes, memories, sims having interests. Relationships that are different form each sim. Example: Sim A likes Sim B but Sim B doesn't care for sim A. I hate how all sims feel the same way for each other. Sims should have different relationships with other sims based on their experiences with them and their personality.