Anyone planning to purchase Secret of Mamo will know it is old, therefore the artwork is not as stylised as later more familiar anime. The artwork is of a piece with Castle Cagliostro, though cruder. What you may not know, and need to know, is that it is a full-length movie, with the same type of pacing as a full-length movie. It's also more “adult” than you may expect, so kids be sure not to sit in the same room as your parents when viewing it. I would rate it 3.5 stars but am happy to round up.