So deep it would require completely seperate games.
*A Sims game with no occults.
*A sci-fi game including the aliens.
*A fantasy-horror game with the vampires and werewolves.
*A fantasy game with the spellcasters, mermaids, etc., etc..
This way they could build better background stories, the world itself and make the occults themselves much different from regular sims. The Sims 4 feels more like an amusement park or a circus and it's difficult to immerse in a world playing a vampire when your sims is doing vampirey stuff then is suddnely talking to Darth Vadar.