"Spawn" is a fantastic comic book with a dark edge and detailed characters, the movie definitely lost something in the translation. For starters: The acting is at 'Baywatch' level (even experienced talent like Martin Sheen was weak), the hero is weak and uninteresting, and the plot almost rivals Batman & Robin's simpleness & cheesiness.
Michael Jai White plays 'Spawn' who is basically a hero you don't get to know well and therefore is unlikeable and uninteresting. Sheen is the 'secondary villain' and not only lacks menace but doesn't seem suited for the role. Most of the other supporting characters aren't interesting, except for Mindy Clarke who plays the voluptuous assassin 'Priest' and is given only minimal screen time.
The only enjoyable character at all is John Leguizamo as 'Clown', a blue-skinned villain reminiscent of Batman's 'The Joker', but is nowhere near as good as that classic villain because 'Clown' relies more on fart jokes and puerile references rather than the memorable one-liners of Nicholson in the original "Batman".
The action sequences are quite good, and while some of the FX are truly memorable there are others that are quite simply pathetic (eg. that awful Maleboglia creature in the Hell scenes, as well as the final battle scene which is very confusing). FX expert turned director Mark Dippe shows he still has visual flair with the FX, but his directing skills need a bit of tuning.
The camera can't seem to hold still on a shot for more than 3 seconds, which gave me nausea during the fast paced scenes. "Spawn" is a film which has about 20% great scenes, 60% mediocre scenes, and the remaining 20% is very bad (remember the corniness element of some scenes in the original "Mortal Kombat" movie? It's on overload here!!).
Like the weak, but far more imaginative "The Fifth Element", "Spawn" has great visual style but poor stories and characters. However it looks far more imaginative and compelling than that movie so it's bearable to watch. If your looking for the cinematic equivalent of a 90 minute commercial, this is your kind of film.