Ignore all these other reviews! I'm here to let you know that this movie is good! Obviously it has it's issues, but this is the first Dragon Ball Z movie to be enjoyable to watch. The first three movies simmer around mediocrity. It's not canon so feel no obligation to watch it. However, if you want some more fun Dragon Ball Z action, this is a worthwhile experience. Let's just address this up front. Is Lord Slug a Piccolo rip off? YES! He is a Namekian. He commands an army (like Piccolo did when he originally took on Earth). He hunts the Dragon Balls to geteternal youth. Slug's moveset is even the exact same. He even uses the "turn into a giant" move Piccolo used. Everything about him is a complete, utter, and unhidden rip off. But you know what, I'm not mad about it. It works. The story was good for Piccolo and it's good here. It's not original, but it's not boring to watch by any means. For a rip off, it does a serviceable job of making it entertaining.

To address another thing. Lord Slug did not go back to Namek to get the Dragon Balls because they used the Dragon Balls to exile him. I know this is minor, but reading other reviews bugged me. This is why. Moving on.

The animation and sound is on par with the anime at the time. The fight scenes are animated well. I love when fights actually have a bit of back and worth and are not entirely one sided. Not to mention Piccolo and Gohan get a bit of time to show off their moves. They are not the best fight scenes, but they stand above a lot of the one sided borefests that monopolize Dragon Ball Z. Sound features your regular Dragon Ball Z tunes. Nothing out of place. Voice acting is solid too for the dub.

Forget the haters. Yes the movie is unoriginal. It's not canon though. Just take it for what it is and I am sure you will enjoy it as well.