DDP's Sprite Workshop

[Crappy Blue Luigi]

it's the face. the mega man face is so iconic and recognizable (especially to sprite artist veterans) that it's hard to see it and not think "yeah, that's mega man."

i can't really criticize your link sprites for having that face, though; it's in style and fitting for the character (both rock and roll have the same face and they're pretty child-like). if you were going for more of an ocarina-of-time-y adult link, then it'd look off.