Just quickly skimming through first episode (sorry I have an impossibly short attention span), I can see what this critic might be referring to. Just the beginning sentence:
"Jake was sitting in his office alone as usual as he handled the fiefdom paperwork when there was a knock on the door."
Dear god I'm going back to to English for this-- Do refrain from using "passive" voice, yes?
Passive: "Jake was sitting in his office alone..."
Active: "Jake sat in his office alone..."
Active voice, to me at least, just sounds more pleasing and I would say it's more common. I can't possibly expect to try and teach you active vs passive without worrying about screwing something up, so hopefully you get the gist, maybe do some more research.
Some more things as I'm reading along:
- For a novel, I consider grammar to be more necessary than perhaps other types of works, therefore I would suggest investing in an editor of some kind, whether that be a friend or family, whatever. Things like commas ("What happened , Peter?"), periods ("It's serious , Brother . The Second Princess was attacked by bandits while she was coming here.")
Just simply grammar like that. It may sound small because it truthfully is, but small things add up, and for a guy like me who had to take an extra writing class in high school, I can easily go absolutely nuts continuing to read this. Maybe I should've started with your more recent episode, but it appears to be that these points remain true.
(reading)
Yeah, me personally, to keep this post from being recklessly long, I'll just impart to you my advice that you attain some kind of editor. Grammar, just... other very general elements, that stuff. After which, I can start focusing on plot-points, but until then, I'm sorry. Best of luck!