They always think they can improve the story by changing things, and they are always wrong.
The casting decisions were awful.
Why is John Faa so short? He is supposed to be a big man with a commanding presence. Same with Lord Asriel. Asriel is not supposed to be a compassionate character. He is ruthless and passionate, but wouldn't be almost in tears when leaving Lyra behind.
Why change who told Lyra that Asriel is her father? This change didn't work and is irritating. So, when she meets John Faa, she already knows this. Bad!
Lord Boreal's role was expanded ridiculously, and his performance was so posturing as to be absurd. Showing Boreal moving between the world's is another big change, and not for the better.
Lyra's initial suspicion of the Gyptians is another change for the worse.
Lyra's escape from Mrs Coulter was changed to climbing out the window instead of just sneaking out the door unnoticed during a busy dinner party.
Jordan college being ransacked by storm troopers was a foolish attempt to build drama where none was needed.
I gave up on this in episode 3.