As someone, who didn't really like Vikings (it was average for me, most of the time it was boring), but loved Ivar and the overall concept of the original show, I didn't really had any expectations about this one. And I think this is the only thing that saved Valhalla from being rated 1 star.
Sadly this show was the definition of boredom. It lacked tension, it lacked really anything. The characters were too weak, they didn't stood out, however they wanted to - except Jarl Haakon, but only because she was portrayed as a black woman. If she would have been portrayed as any other viking, she could have been an other one of those average characters as her companions. Not even the main characters were interesting enough. Leif was too silent for most of the time, Prince Harald was just too much, and the actor played his role too badly, and he had the cringest scene of all time. Freydis... well, with her, her character arc could have been better, too bad this show lacks the same as its origin: good time management. Freydis was a hunter, and overnight she became a fearsome shield maiden. Prince Harald and Leif became insta-brothers just because our Prince lay with Leif's sister. One moment Freydis doesn't like Prince Harald, the next she is in love with him...
Not much is going on on the english side too, unless you count Edmond. I think he could have been a great character, but thanks to Godwin... well, let's not say just anything. And of course Godwin, I don't think he has any logic behind his acts. I mean I couldn't figure out his motives. I thknk they wanted to create somebody like the Kingmaker in Henry VIII's time, but though they chose a good actor for him, Godwin (and the whole series) has the main issue: we don't get to see their inner motives, the behind the scenes. With that, the show could be better.
So lack of good story telling, bad dramaturgy, and boring characters with average actors - Valhalla could have been a great show, the main story behind it is interesting (chatolic vs. pagan vikings), sadly it lacked even those tiny good things that the original show could stand out with (great characters, interesting myths and worldbuilding).
Not sure, if I'm going to continue with this one.