With his realistic depiction of this dysfunctional family, Ibsen pushed the envelope like the South Park guys do. He wasn't afraid to show families as they are – sometimes ugly and unseemly. In Ghosts he encourages everyone to stop playing Mom, Dad, and Son (or Daughter) and to relate to each other as human beings.
In its rejection of familial loyalty for the sake of tradition, Ghosts is just as radical now as it was in Ibsen's time.
Engstrand and Regina become codependent foils to Mrs. Alving and Oswald.