To make a good life sim, it needs to have one thing, a large amount of players. My guesses are byond isnt popular enough yet for a decent game to get over 50 players. And as a guess, i'd say your game would get 5 maybe 6 players most of the time, and if its a life sim, no NPCS then it means you've got 5 people in the whole city, you dont think it'll be a bit EMPTY? So whenever you want to go buy groceries you've got to go find someone who sells them and it would be quite a challenge.