These aren't for anything in particular, I just did them for the sake of doing them. I made as many as I could until I got bored- turned out to be 70. You may notice that many are basically recolors of others. I did this because I thought it would emphasize the iconic style of the sprites. In other words, I did that as a style choice, not because I was lazy.
Draws a lot of inspiration from these: http://www.pixeljoint.com/pixelart/55047.htm