Neptune aka Purple Heart in the video game world has a human form. All of the console goddesses in Super Dimension Game Neptune do and Compile Heart released new concept art showing the girls as girls.
Human form is on the left and anthropomorphic console goddess is on the right.
Belle / Green Heart
Blanc / White Heart
Noir / Black Heart
Neptune / Purple Heart
There’s much more art in the official Neptune artbook. Reserve the game and you get a 40 page Neptune visual book as a bonus.