This one is so hard for me because I absolutely loved the series.
For all the viewers with knowledge of the series, this movie makes sense. It will be disconnected otherwise. It almost needs two separate reviews.
The acting was decent-ish. Most of the characters were missing something that they had in the series. I don't think the acting was bad, it just wasn't "right". I'm not sure it's entirely fair to say it's all acting. It would only be fair to attribute some of the lack to the script.
There were bunches of characters running around who were not even close to necessary to the plot and they had little to no back story. Fine for the fans, but as a free standing movie, not the best idea.
The fan wants to give this show a 4, but as free standing movie it's a 2 / 3 at best.