Undoubtfully the climate. This leads to Singaporean malls being 100x more interesting, convenient, high-end and better looking than any US mall. Pretty much all

Undoubtfully the climate. This leads to Singaporean malls being 100x more interesting, convenient, high-end and better looking than any US mall. Pretty much all large malls have direct or adjacent to public train transport (MRT at Vivo, Ion, 313, nex...), have high-end restaurants, mid-range and fast-food offerings (local and international) and a wider variety of stores. They also have air conditioning, which is pretty much the only reason why all life happens in malls and you can barely walk around on weekends ;)