When I heard that it had the writers of Lost, I was kind of hoping for it to be a bit darker, as well as a bit more mysterious. The acting isn't as strong as Lost, nor does the show have a cinematic feel. A few segments actually seem a bit low budget. However, it has a lot of potential.
A few suggested changes:
1) It is strange that the characters in the fantasy world act/speak like they are from modern times. It seems a bit fake. Make it more raw. Don't give it a Disney-fied vision of a fantasy world.
2) Some of the indoor scenery in the fantasy world seems low budget.
3) So far, there is no comparison between the Mayor and Ben Linus from Lost, who I think are supposed to play somewhat similar roles. The character of Ben did a better job of making you wonder "How much does this guy really know?" Ben advanced the story even when he wasn't speaking.
4) They should have done more to see Snow White bonding with Charming when he was in the hospital bed --- That whole sequence ramped up way too quickly. It wasn't believable.
5) It needs more of the boring, everyday scenes from Lost where you get to know the characters and take a liking to them. Intersperse some "action" to keep those action fans happy, but let the story plod along when it needs to so that we start to care about the characters.
6) Make better use of the commercial breaks, as well as the end of the show, to knock the viewer's socks off with a new plot twist.
7) Silence. More of it. Explore the different worlds. Tell some of the story through actions and expressions. I literally think the show would be better with 15% less dialogue per episode.