I agree, a great show. A great 80's vibe throughout, dark undertones and a fantastic ruined parallel universe (it made me think of Silent Hill in many aspects). The children absolutely steal the show and the story is nicely rounded within these 8 episodes. I liked that. No cliffhangers, just an open road for a season 2.
What I didn't like, however, were the performances of the adult actors, especially Winona Ryder. She was pretty unconvincing and I couldn't stop imagining that actress who played Ray's wife in Everyone Loves Raymond in her stead. However, maybe that's also a part of the 80's feel. Her average acting emphasized children's performance.
All in all, (ignoring the Ryder hate) a great show. I am looking forward to seeing where it goes in season 2.