It always makes me smile when I hear the term "8-bit" used to describe art. The strict hardware and software limitations of early computers spawned a complete visual aesthetic!
And I have to disagree to the fact they all look the same. When I watch Super Meat Boy, Shovel Knight, Void & Medler, Swords & Sorcery etc. they have really distinctive design.
Super Meat Boy is an example of the visual sameness in my opinion. It looks exactly like Broforce or Super Time Force Ultra or a million others. The aesthetic seems to be 256 color VGA with really tiny sprites. It doesn't really remind me of anything or look inspired by anything in particular IMO.