I thought the voice casting was well-done; my only problem was with Anne Heche's performance in the first scene or so with Lois; it felt very stilted and unnatural, and really could have used another take.
The plot was very different from the comics, but it wasn't until I saw this that I realized just how different it would have to be, due to the crazy things that were happening in the Superman comics at the time. Consider the following important aspects of the Death and Return story in the comics:
- Lex Luthor was "dead," but living in a cloned body and posing as his own son.
- Lex Luthor II was dating Supergirl, who was a shape-shifting superpowered clone of Lana Lang from a pocket dimension.
- Clark Kent and Lois Lane were engaged.
- A secretive hi-tech cloning operation called Project Cadmus was a major behind-the-scenes player in Metropolis, and were responsible for a society of sewer-dwelling monsters, as well as the grave-robbing of Superman's tomb.
- The Justice League consisted of more or less the Keith Giffen team, who are largely unknown to the general public. They were brutally beaten in the Doomsday battle.
- The Eradicator, a sentient Kryptonian artifact dedicated to the preservation of Krypton, was lying dormant somewhere near Earth.
- Hank Henshaw, an astronaut, had previously encountered Superman after a failed space flight which left him and his family dying of radiation poisoning, but also gave him the ability to control machinery.
- Pa Kent suffered a heart attack shortly after Superman's death, and Superman's return from the grave was preceded by a battle alongside his father on the way to the afterlife.
And if you eliminate one thing, several others necessarily fall thereafter. Take out Lex's clone (a necessary decision, I think), and you have to remove his relationship with Supergirl, which makes her an utterly superfluous character to the story. Remove Cadmus, and you remove the whole Underworld subplot, Lois Lane's infiltration exploits, the Guardian, and Superboy. Ultimately, the plot ended up very streamlined, thanks to some of these editing choices.
I was surprised and impressed at the way they were able to roll up three of the four Supermen into a single character--a clone (Superboy) with incomplete memories and a more brutal idea of justice (Eradicator) who ultimately betrays the populace and must be taken down by the real Superman (Cyborg).
I really liked the black costume and Superman's headbanger hair (which I really don't think qualifies as a "Supermullet," it was generally drawn long all around); along with the electric blue costume, that look needs to be present in the DCU. I know the days of the dark-colored violent antihero versions of other characters (Venom, Vengeance, Strange, Thunderstrike, etc.) are over, but there's got to be someone to wear the black-and-silver outfit. Hey Kon-El, need a Kryptonian recovery suit?
Overall, I thought the film was pretty well-done. It compressed and adapted the story nicely, included some great battle scenes (and some real shocks, like with Luthor and Mercy), and more or less met my expectations. I could have done without some of the campiness of Luthor's framing monologues, but that's a minor quibble. It's no "Mask of the Phantasm," but "Superman: Doomsday" makes a decent intro to DC's newest animated endeavor.
And I can't wait for "New Frontier."