Dragon Ball Z movie 2 The world's strongest is about an evil scientist Dr. Wheelo of whom only the brain is left wanting to transfer his mind on the body of the worlds strongest.

Like most Dragon Ball Z movies, this one can't fit into the main timeline but can be watched after finishing the Saiyan Saga. Like many others, it uses homages to recently used techniques of the most recent arc.
The appeal of the movie is also that this is the only time Master Roshi is involved in fighting in the Z era since he retired in the original Dragon Ball from fighting since the younger generation all surpassed him. But because the antagonist still believes that Roshi is the world strongest, he ended up being involved giving them a reality call when that turns out not to be the case.

The henchmen in this movie also possess unique powers and giving visually amazing fighting scenes where Goku has to use a move for different reasons to overcome these powers.

The main cast of characters behave as they do normally. Gohan struggles with his needs and wants meaning his studies or spending time with Piccolo. That being a trend in the movies continuities of Dragon Ball. Krillin would usually help him out in combat while Piccolo starting the tradition of coming to save Gohan from whatever.
Goku is his generic heroic self which is typical in DBZ movies.
Dr. Wheelo is very analytic and doesn't recklessly rush into action unlike his assistant Dr. Kochin who is a close friend who did a mistake that cost his life despite Wheelo's warning.

The movie struggles to stand on its own. While Dr. Wheelo has a unique goal, he is still a Dragon Ball Z villain who does what most Dragon Ball Z villains do when cornered. Another thing is that the movie doesn't have any grandiose moment in the final. The fights are good but nothing feels amazing enough to go back and rewatch it since most of the best scenes are homages. Even the Student-Mentor Kamehameha isn't remembered well by fans which is unique to this movie.
There is also the confusing part with timeline placement. While DBZ movies are considered their own story far removed from the main plot since they can't fit in, there are references made directly about stuff that happened in the anime which can confuse viewers.
Lastly how Wheelo is defeated is similar to how many other movie characters get defeated which can't be used against the movie since it is the first time it happens but doesn't make it any better.

Overall to get most out of this movie, you need to watch it before the movies that come after it since it will end up feeling repetitive. It is still a good movie and if you haven't you should give it a shot.