Dragon Ball GT Special Goku Jr is for some reason advertised or sold as a movie in some countries. It's a story taking place 100 years in the future after Baby's defeat and focuses on Pan's grandson Goku Jr. A timid boy who gets bullied at school and can't defend himself for shit.
One day Pan gets ill to a dangerous degree and is hospitalized to the point he builds up courage to hunt for a Dragon Ball which suppose to be on Mount Paozu.
On his way he and one of his bullies have to overcome challenges such escaping from witch.

It is very adventure focused and about learning independently. Goku Jr has not only learn to overcome his fears but also stop believing everyone.

Puck may be an interesting character for the story but not someone who would want to see when you watch Dragon Ball. While he is Goku Jr's bully, he admires Pan. When he saw Goku Jr overcome his fear in one scene, he felt like helping him out with life advices. Those making him more than just a kid who uses his power to get what he wants.

The enemies aren't very striking and more comic relief. Mamba is a crafty witch. Her henchmen have personality but are rather forgettable since they don't do much.

During the special, Goku also awakens some weird power from time to time like any hybrid Saiyan. There is a certain mystery around it that may let you guess what is going on and at some point it seems like he is a completely different person. Depending on how you take it, it can ruin you the experience or not.
While the final fight isn't anything impressive after what we have seen so far, it has some satisfaction.

Animation and music is great. The quality does fit the movie standard and I did enjoy quiet a bit of it.

Criticism is probably for people who this movie isn't for. This isn't your average Dragon Ball Special with a slice of life story or action packed continuation with people fighting using planet scattering punches. Especially since the final bad guy can be held at bay by an adult bear. Even compared to someone like Tao Pai Pai they don't feel like a threat.
While there is comedy, it isn't the type of humor you are used to from Dragon Ball, Z or GT. And if so, they aren't funny to the level you would look back at the jokes with Master Roshi or Oolong. Nor are the characters as oblivious nor live under a rock like Goku at the start of the franchise.
And the final antagonist is some generic badguy that appears out of nowhere as a final boss taking away from the challenge to beat Mamba and her goons.
Lastly the ending is kinda making this adventure feel pointless, unless you see it as a reward for Goku Jr overcoming his fear and the mystical things happening when he finds the 4-Star Dragon Ball.

Overall, it is a good movie for what it is. But if you want high stake fights and clashes that blow up the environment, or the clash between ideas of characters... probably skip this.