Even Astro Boy's grainy and jumbled look is disappointing. It's not so bad that you can't tell the dirty scrap yard from the pristine Metro City, but there's a severe lack of detail in just about everything in the game, including the enemies, cities, and Astro himself. Likewise, the voice work (by actors who lent their voices to the film) are just there as a means to remind people that this game is indeed based on a feature film and their performances reflect that fact.
On top of all that, it doesn't take much more than an hour or so to complete the entire game on normal difficulty. All of these things create a game that shoehorns Astro Boy's super abilities into a completely unremarkable experience.