Animation quality is 50/50 for me. The flash animation is annoying but it can look really good when its good and really bad when its bad. The best scene that most caught my attention was the one where the Devil is tormenting King Dice, which feels like some classic Fleischer scene. I think I wouldn't mind the animation as much if the picture didn't look so clean when compared to the games which did a great job of getting the picture quality right and making it feel like an old film reel, although I do appreciate the dirty film filter they added a lot. But like
@Professor G. Raff said, the lack of constant motion is what hurts it most, and its been shown that flash animation can achieve that to a degree. I know traditional or authentic looking animation is more expensive and time consuming but it would've been nice if the show at least looked like the intro more often or at least didn't have the characters be still so much.
The characterization is pretty hit and miss for me too. Cuphead and Mugman are really likeable, along with some of the villains, but the Devil, Porkrind and Miss Chalice just feel pretty underwhelming. Porkrind is portrayed as a complete douchebag with murderous tendencies instead of an ally or a standard greedy friend, something that meshes well with what we see in the games. Miss Chalice seems to be a straight up crook rather than someone looking out for the cups, I mean yeah they could change that in the next season, but from the set up its clear that she's just some ghostly crook looking out for herself who has even less in common with her game counterpart. The Devil is probably the most disappointing though since he seems to just be your standard recurring villain instead of reserving that role for King Dice while keeping the Devil as the behind the scenes bigger bad to maintain his sense of looming intimidation.
And I guess that characterization of the show's main villains is what brings me to my next point. The show would probably have been way better if they had kept the casino as the main plot point and recurring location, which would've allowed them to interact with the other game bosses more seamlessly and also giving the Devil and Dice a more proper reason to hound Cuphead and Mugman. But apparently they couldn't do that due to this moronic new age rating standard that prevents kid media from having casinos in it despite that Cuphead is probably the biggest anti-gambling ip in recent years. The lack of a casino also keeps them from adapting the plot of the game in a decent way so that's a bummer.
