Complex sentence: Originally, Tad Williams conceived Shadowmarch as an idea for a fantasy movie and later a fantasy tv series, which might have been described as "Hill Street Blues meets Babylon 5 meets Lord of the Rings".
Split into simpler sentences: Originally, Tad Williams conceived "Shadowmarch" as an idea for a fantasy movie and later a fantasy tv series. "It's Hill Street Blues meets Babylon 5 meets Lord of the Rings".