The movie is the highly compelling tale of how a whiny, entitled brat turned to evil. "Why haven't they made me the youngest Jedi master in history yet?? They must hate me! I will turn to the Dark Side!" said Aniken. Yoda replied, "Stilted the dialog is. Violent the movie is. Script writers to the dark side have also tuned. Stopped they must be. If anything to say about it I have." (ok, that last sentence is an actual Yoda quote.)
Moral of the story: don't leave your former pupil for dead while he's one fire with has arms and legs cut off, cuz medical technology might be able to save him. It cannot however, save a woman who has lost the will to live because she is Ophelia and weak and must die. Also, prozac had not been invented yet a long time ago in galaxies far away. Secondary morals: excruciating levels of violence (including against children) is perfectly fine kiddie fare as long as the romantic subplot involves nothing more than hand holding. Sex is dirty. Violence is problem solving. Also: don't trust clones. And the troubled young warriors who occasionally slay unarmed prisoners and entire villages may have issues that ought to be a bit more apparent to their mentors.
The best part of the movie is when a lightening bolt strikes Darth Sidious' secret laboratory and his monster rises, breaking free of his restraints and smashing everything. "It's alive! It's alive!" Sidious screams. The second best part of the movie is when the black knight is de-limbed and clawing at the side of the volcano, screaming "I hate you! Come back! I'll bite your legs off!" Obi Wan says, "What are you going to do? Bleed on me?" Mysteriously, none of the folks whose limbs are amputated by light sabers bleed. It must somehow cauterize the wound as it slices. There were much better arms conventions back in the day, far far away.
but seriously, Darth Vader is calm, cool and badass. He's hateful, but more in a Dick Cheney sort of way than an angry, drunken teenager sort of way. Aniken Skywalker is not Darth Vader. He's the prissy rich kid whose parents sent him to boarding school after he crashed their third new Mercedes at age 15. He's the kid with the cocaine hookup who pays other people to do his homework for him and complains his teachers hate him. Those kids don't grow up to that kind of power. (President maybe. Supercool super villain. no.) Darth Vader should have been a misguided youth in his day, but in an institutional way. He was in the Hitler Youth and the luftwaffe, but claims to have deserted before he started climbing the ranks of his religious organization. That kind of evil. Not the drunk and passed out on the railroad tracks, feels entitled to own the world kind of evil.