It may not beat the original Wizard of Oz, but it is ten times better than the first Tom and Jerry crossover with The Wizard of Oz.
The movie wouldn't be so good without Jason Alexander, who plays the evil Nome King that steals the movie a lot as what Jason Alexander did with Hugo in The Hunchback of Notre (1996), made 20 years early as another film that stars Jason Alexander and also pays homage to the late Mary Wickes (the live action model (not the voice) of Cruella De Vil and the voice of one of the puppies in 101 Dalmatians (1961)) who voiced one of Quasimodo's gargoyle friends, Laverne, as her last film since she died in production before the film's release. Speaking of a film paying homage to the deceased actor who died before the film being released, Tom and Jerry: Back to Oz pays homage to the late Joe Alasky who died in production after recording a lot of dialogues as the Wizard, Droopy, and Butch.
The music, songs, cast, animation, colors, and special effects were so well done.
I thought the story was decent because it doesn't always have to focus on Tom and Jerry. And you know why is because after Dorothy and Scarecrow are both captured by the Nome King, Jerry and the other mice soldiers saves the Tin Man from drowning and goes to the Emerald City while Tom went with Lion and Toto, who later met the Tiger of the Forest along with her animal colleagues and later catch up with the allies.
All the characters from The Wizard of Oz (including Dorothy) are also getting better character development and more screen time than in the first crossover movie between Tom and Jerry and the Wizard of Oz so this film did balance the screen time between Tom and Jerry and the characters from the original 1939 movie
Despite Tom and Jerry having minimal screen time, the Jitterbug is also featured after being a deleted character from the Wizard of Oz. He's also dressed up as the Mask.
If it weren't for Jason Alexander, this film would not be so good to watch! With all the reasons I said and don't pay attention to the critics, this film really deserves to have better reviews than the first film.