The Enchlore Machine

[DragonDePlatino]

Notice, though, that the thick lines in Yoshi's Island were only on the backgrounds, and not the characters.

Well...that screenshot was a bad example, but a few of the enemies have the thick outlines I'm talking about, like the Pirahna Plants and Large Mildes.

But of course, I wouldn't recommend throwing out the rules of pixel art and going with thick outlines. The only reason Yoshi's Island was able to pull off the bad palettes, poor shading and jaggies was that it had a very good art direction. Individually, it's graphics were unpolished, but taken as a whole the game looked gorgeous.