It's not the first time this happens with series, the first episode looks amazing, and right from the second one, the whole thing changes, the production is cheaper, the whole product is different..
With this show in particular, I didn't mind so much because the episodes are unitary (actually, two stories by episode) I could enjoy the first one as a little movie and ignore the rest, as there's no story ark between them.
Still, after seeing how good the first episode was, excellent production, cool actors, lots of Easter eggs, simple but interesting stories, beautiful cinematography and great (surprisingly good!!) CGI, watching the rest was an absolute disappointment, in every aspect I named before.
It's a watchable show, I did watch the whole season, but some were quite bad and boring.
I can only recommend the first episode, and just imagine the series was all like this but just dream about it, skip the rest to avoid disappointment.