The set-up: The PCs are on the bad guy's orbital space station which has nuclear missiles. The bad guy's doing his speech, when one of the heroes cuts him off. He responds, 'if he speaks again, I launch a missile'. The hero goes 'oh yeah?' and the sound of a missile firing results. The bad guy then demands they surrender and swear fealty to him or he launches the rest. The heroes refuse, and the rest launch.
One of the heroes (uber invulnerable dude) breaks open the side of the station, leaps out, beats all the missiles away, and lands perfectly on the ground (has wire-fu flight). One hero puts up a force field to prevent everyone else being sucked out. The bad guy escapes, the world is saved, no problem.
I was a little stunned hearing this.
Me: The guy was able to survive re-entry?
GM: He's got immunity to fire
Me: And the solar radiation?
GM: That too.
Me: And the vacuum?
GM: That too.
Me: And the impact?
Me: ... okay, so how was he able to leap the distance to the missiles?
GM: He has super jumping.
Me: Which can break the orbital speed of the space station to catch up to the rockets going towards the earth?
GM: *pauses* You'd have done it differently, wouldn't you?
Me: Well, yes. The fact is, the guy'd have broken up the side of the ship, and everyone would have been sucked out. They'd all be spiralling off into space.
GM: Well, a few had flying.
Me: Which is fine. They just need to deal with everything else. And of course, trying to figure out how to get into re-entry. And it would depend on how their flying works.
GM: But I had an NPC mage make them all immune to space.
Me: ... *sets that aside* Then there's the fact the hero going after the missiles wouldn't have been able to keep up. They'd be a few thousand kilometres away, watching the world glow. The space station would blow up of course, self-destruct switches being what they are, thus the heroes would be adrift in space with no way home.
See, I don't mind a little suspension of disbelief. Just... gah.
There, I feel better.
I think that's why I don't tend to enjoy super hero games. My idea of a super hero comic is something akin to The Authority, or hell, even the Ultimate line from Marvel. The idea that sure, you're a super hero, but that doesn't give you carte blanch, and yeah, if you screw up, people die horribly. I like that. Just find it really hard to find someone willing to run that.