The Bad Guys movie was really enjoyable and charming, plus the beautiful animation but what happens if you take the fun heist antics of the bad guys and take away the great animation? Your left with what feels like the cutscenes of a 2000s licensed bad guys video game.
The holiday special itself is a basic but enjoyable time that still has those characters and the heist fun that came from the original film. I do think that the limited animation definitely hinders the special as the original film had a unique and fun visual style that they try to emulate in this special, for the most part all the character designs do look good and match the films style but the rigid movement and somewhat choppy animation makes it a bit disappointing as a follow up/prequel to the movie. I do think this was do to the special having a lower budget which is something out of the control of the animators.
Overall I think it's a fine enough special that kids and adults can get some enjoyment out of during the holiday season, but not an instant classic like Charlie Brown or Garfield's Christmas specials.