Although the show’s setting is a fantasy with fantasy characters, the producers don’t balance everything out. For example, when Emma comes to Storybrooke there was a lot of drama because she is the mum of Henry and a lot of people know it but she doesn’t. In another episode, it was only the flashback of two characters, which is good sometimes, but it would be better if we saw how this affected anything, which would add to the drama factor.
There aren’t very many creatures in Once Upon a time. It's mostly just the princes and princesses or any human in any fantasy story. One of the rare occasions that it has shown a creature would be a dragon, and it didn’t have much screen time. Also, most creatures aren’t talked about in the show, the dragon was the most talked about creature. Another rare creature in the show is fairies, but they only show up every once and awhile.
In Once Upon A Time, the producers go along with the story. Snow White and Prince Charming are together, the guy wakes up the girl laying in the middle of the forest or castle with a single kiss, it’s just the cliche. There’s nothing to make you wonder what is the real deal, unlike Supernatural where they give you a lot of plot twists and reality