- Open world and Create-a-World, including tools to modify the environment (add/remove/edit bodies of water, hills/mountains, forests, roads, etc)
- weather
- more animals your sims can interact with, not just pets (e.g. wildlife like foxes, badgers, raccoons, bears, wolves, ravens, squirrels, deer... even some exotic ones to allow to create worlds that aren't necessarily inspired by Europe/North-America, so tigers, elephants, crocodiles, kangaroos, koalas...) Wild animals would be NPCs but some interaction should be possible (they are wary of Sims, and flee or attack if approached, but sometimes they could be befriended with patience and by offering food...)
- more cultural/ethnic variety (building styles and clothing inspired by different cultures from around the world)
- easy way to switch off an EP, i.e. play as if it had been uninstalled. Some game packs change the gameplay in significant ways (e.g. vampires, magic, the eco-friendly EP in TS4, etc) and at times it is nice to play without those elements.
