We’ve seen a lot of films (from Marvel and others) with planet level threats, but I think there have been some elements missing that hopefully this film can pull off better.
The big one to me is Earth-threatening events never feel as intense as they should. No films I can think of have really felt like: “This is it. This is serious. Everything we know could end.”
We also haven’t seen a cold, emotionless threat.
Typically, even if the threat is alien, there are human-like emotions/motivation behind it all.
There’s something particularly frightening, for example, about getting eaten by a great white shark. You’re simply food to it. Your fear and emotions mean nothing to it.
Thanos, Dormammu, etc. have plans, schemes, motivations etc. that we can relate to on some level.
Galactus, if done right, is completely emotionless. He’s not thinking: “Should I do this? Is this the right thing? Should I consider something different?”
His consumption of a planet is a simple act that he hasn’t put any thought to. The lives affected are completely meaningless to him.
I’m hoping they can pull that off to give us something different than we’ve seen before.