Galactus is kind of hard to explain. It is more like a some kind of cosmic machine that operates these long, parasitic tendrils that are made of some kind of cosmic dark matter. It looks pretty fucking cool, actually. And when it passes Saturn, you see a silhouette of the classic Galactus helmet on the planet's surface, which I thought was a neat nod to the comic book fans. It works really well in the film.
Honestly, the Silver Surfer is handled so fucking well - and I really mean it, he's worth the price of admission alone - it's kind of infuriating to see Doctor Doom be so horribly mishandled and reduced to a lame, made-for-TV villain. In fact, the Silver Surfer shines so bright in his presence and origin, that the dull parts of the film seem even more grating considering how awesome the Surfer is handled.
