I was excited to see this. Sadly though it was only a limited series (as in one series) and it only had 10 episodes, and the whole 7 episodes were wasted with the characters stuck in the past.
Plus, this character Douxie; we didn't know much about him other than his frequent appearances in Trollhunters and 3Below, and then suddenly we see his full story in this one, but it felt sudden. And that's my other critique; the whole thing was rushed.
And finally, while I am happy that Jim is human again, I felt that it spoiled the finale of Trollhunters though (I felt it was a disrespect to the late Anton Yelchin).
But those were just the cons. My pros for this were the full cast, the epic fight scene between the knights and the trolls, and the surprising origin story of the first Trollhunter.

It was pretty good though. I just wished though that the whole thing wasn't rushed, and there would've been more than one series.

Well, at least we got Trollhunters...
3Below was a big letdown - just as it started to find its footing at the start of the second season it obviously succumbed to rushed schedule and cancellation of 3rd season. They can claim 2 seasons were always the plan all they want, but it's pretty obvious how they rushed through plot points in the second part of the season they just condensed season and a half in half a season, but on the other side they wasted a lot of season 1 on filler episodes. Even if they got another season it would never have reached the heights of Trollhunters -
characters while likeable never clicked in the same way.

And then we got Wizards. A major step up from 3Below, it hums and sings for the first half of a season. It really builds up everything beautifly. All the conflicts, character motivation, world and history. It truly reached Trollhunters level from the get go... And then it all comes crashing down in flames. It is essentially the same problem the 3Below had - too much to tell in too little time. Problems arise and solve itself literally in a matter of minutes. You never get to really process what some twist or hurdle means to the story, it's already gone. There's no room for a story and world to breathe and consequently there's no chance for a viewer to care. Those plot points we rush through are the seeds of a great story, if only it got time to be properly told. It truly could have been Trollhunters level of great.
In the end I had to force myself to watch the last couple of episodes, and I've drawn it out over weeks.
Terrible end to something that could have been really special. Arcadia deserves better.