What are you all grumbling about? A cloud? Where was there a cloud in this movie? I didn't see any clouds. All I saw was a giant CGI alien in armor and helmet towering over the Earth and challenging the Surfer. He was there as plain as the ring on my face!
Nothing but a shadow? Um, guys, maybe you walked into the wrong theater and were looking at George Clooney in Ocean's Thirteen, but by gosh, I sure as heck could see the Jack Kirby-style Galactus in this movie...
Wait a minute. Let me look this up. Hmmmm...Google...G-A-L-A-...okay, hold on...whoa, what's this?:
As a being who is both an abstract entity and a physical creature, Galactus' true form and nature are beyond the capability of mortal beings to comprehend. Sentient beings perceive Galactus's physical form as they most imagine him to be. He may appear to be an amorphous or non-corporeal being to some observers, while others may be able to perceive him as an armored giant towering above them.Or, as that famous John Byrne page puts it:
Each mind that views him struggles at best it can to perceive that unguessable force as an image it can comprehend.
Well, there's your problem. If you didn't see a big giant guy in a helmet...well, you've got no one to blame but your own myopia.
Man, I bet you guys didn't even see the awesome CGI Jack Kirby getting turned away from the wedding alongside Stan.