To quote Dr. Dayafter:
Imagine, if you will, a place where The Shadow stalks the night, preying on those that would do us injustice. Where The Rocketeer soars over the city, combating some evil villain that is hell bent on crushing the government and taking over the world. A place where Sky Captain, flies at break neck speeds to do battle with invading forces. A city with hot jazz and cold gin, served on the sly because of prohibition. Monstrous Art Deco style buildings dominate the landscape with the city's elevated train zooming between those buildings, taking citizens to their various destinations. Old cars putter down the streetand fire hydrants in the tenement areas are opened to afford some cool relief from the hot days.
The lavish Art Deco designs and skyscrapers of the 1920s and 30s exhibit a feeling of progress and a sense of optimism after the austerity of the World War and its aftermath.
Add to that an attractive alternative history, and Seraph City has the potential to be a winner!