[quote=@Primal Conundrum]
Guardians of the Galaxy was middling. It suffers from one of the worst cases of "our aliens are just regular people with different coloured skin and a costume scalp" seen in recent years.
[/quote]

Quality of the movie aside (I personally loved it, though I dislike the effect it's had on the comic counterpart to a degree), this has been the case with comic book aliens since [i]Superman[/i], whose only "alien" feature tends to be how absurdly blue his eyes are unless he's wearing the Clark Kent glasses. And that's kind of a throwaway trait.