The first episode was good because it was setting things up and stuff was happening. Then nothing much happened until the last 15-20 minutes of the last episode. Most everything in between should have been done in 30-45 minutes. Visually, they did well but it'd so poorly written nothing was memorable and there's nothing there to pull you into the story.
The whole thing feels like a slow crawl until they get to the actual story and just when you think you'll get a payout for watching hours of character introduction, it's over in 5 minutes. It's the most underwhelming thing I've watched. Imagine if LOTR was just the Fellowship walking the trail, watching them set up and tear down camp, hunting, and other minutia for hours until they get to Moria and then you get 5 minutes split between entering moria, the room with Balin's tomb, and see the flames of the Balrog before the Fellowship makes it out. You don't actually get to see the Balrog, just get to know that it's there and that it's gone.