To answer that question, we got a significant amount of explicit white walker action. Basically more than anyone ever expected to get this early. It's good.
It came so out of left field that I need to re-watch it for a fair assessment. Coming where it does in this season, it felt like supernatural overload. I'm not complaining... I just don't think I've properly processed it yet.
The spellcasting scene at the end of "The Children" (where one of the titular children started zapping/exploding a bunch of walkers) had an entirely different effect on me. It blew my mind and made me more excited than any other supernatural scene in the entire series. It was similarly out of left field, but it was so well-done (the sound design was masterful), and more important, tightly-packed and brief. It truly felt like supernatural things suddenly happening in a real world.
In the setpiece last night, it was something we had sort of seen before, but in a far more terrifying context, where the walkers posed an actual immediate threat to a bunch of important characters. The effect was dread and anxiety and a bit of hopelessness, like how are they ever going to overcome this enemy?
That (rather than the actual battling) was the strength of it, and I'm glad they ended on that note. The moment where Jon Snow, terrified, met eyes with the white walker across the water, was classic.
I have mixed feelings about the rest of the episode. I was so looking forward to the Tyrion/Daenerys matchup, but I can't help but feel like it landed with a thud. I mean, I guess it's completely realistic that Tyrion's speaking gets hyper-formal and awkward, but unfortunately I think it sheds a stark light on Peter Dinklage's terrible accent. It was pretty bad last night. Also the first interaction didn't feel particularly true to his character (perhaps because they're beyond the books here). Things improved significantly in their one-on-one meeting... I was so relieved when Tyrion finally made a joke, and Daenerys dealt with him in a way that made sense. I can't wait until they get more comfortable with each other and Tyrion can move past his stilted talk for good, because theirs could be one of the best duos. Maybe they need to bond during a road trip.
Jorah's life choices have seriously begun to annoy me, but at the same time his character is becoming more interesting with each episode. Anyway I wonder if dragon blood cures greyscale or something like that. Another hand-amputation would be redundant.
Arya
right now I don't really understand her story, I read somewhere that by the last episode everything will make more sense, she was by far one my fave characters but her last episodes have been a little dull.
From what I understand, Arya is sort of auditioning as an imposter, trying it out without actually using someone else's face yet. The point, as per the two-faced god, seems to be to bring justice in one way or another. That's why Arya is so excited about this, being really into revenge and whatnot.
Cersei
it's crazy but I want Cersei to have her revenge, she's evil and dumb but I want her to succeed on this one, how the hell will she get out?
remember back in the first episode Qyburn had ''something'' at his table, I believe that is the mountain, will he use him for her rescue?
I like that prediction. I just hope it's different enough from Frankenstein's monster.
Surely Qyburn can pull off something else, like gassing that whole place. Isn't he into chemical weapons?
I would still like Baelish to be involved in the resolution, which could very well end with Cersei being out of power.