Masters of the Universe contains very little in the way of originality which I suppose should be be expected for a film based on a toy. The plot and characters are recycled variations of Star Wars, Conan the Barbarian, and Flash Gordon. Hell, even the music feels lifted almost note-for-note from the Superman movies. Masters of the Universe lacks the conviction of these other properties and just feels hokey.
Let's be frank: Masters of the Universe is a pretty bad movie. The science fiction and fantasy elements are wholly unconvincing, performances are mostly weak, the entire production reeks of cheapness, and like most things involving He-Man, it is hilariously homoerotic (if you don't believe me, watch the scene where He-Man explains to Courtney Cox what the Cosmic Key looks like and the heroes' choice of automobile). That said, I do enjoy Masters of Universe. It's entertaining in a campy way, a mostly inoffensive bad movie that's easy to make fun of, and it does contain one element worth lauding: Frank Langella's performance as the villain Skeletor.
In a role whose primary attractiveness was most likely the paycheck, a role that is clearly beneath him, Langella gives Skeletor his all, overacting outrageously as one would expect for a villain who desires to rule the universe. He is so over-the-top and intense that it is impossible not to enjoy watching him devour the scenery. He's having the time of his life making all these boasts, declarations, and sneering threats; it's like he saw Terence Stamp as General Zod and thought that was too subdued.
The central problem of the movie is transplanting so much of the action from Eternia to Earth. When I watch a science fiction fantasy, especially one in the space opera mold like this, I want to be swept away to an amazing new world. Look at Star Wars and Star Trek, for example, filled with so many incredible sights and creatures. Masters of the Universe portends to be about an intergalactic war between He-Man and Skeletor, but He-Man feels oddly subdued and de-emphasized as a character. More time is spent on Julie and Kevin and their mundane lives - her parents are dead and she wants to leave town, and he's in a band and doesn't want to lose her - and frankly, it's boring.
Laser fights occur in record stores, and Skeletor's force march down main street, something that conveniently goes unnoticed by anyone in the neighborhood.
Julie also falls for the same trick Dark Helmet used to capture Princess Vespa. One is tempted to think Mel Brooks was poking fun at Masters of the Universe, except Spaceballs was released two months prior to Masters of the Universe. Sadly, Brooks' comedy is actually more plausible in this regard; at least Vespa knows her father is still alive.