What do you think I am, a Genesis programmer?
Actually Joe, you bring up a good point. Since the Turbo has many more colors available to choose from than the NES (which is the most popular creation with PixelBlocks) creating sprites with only 20 colors can be more difficult...
...however, it can be done with minimal loss in color and still look really close to the original. The next sprite I want to create is the ship from Soldier Blade. Below you see the original sprite on the left, made up of 17 colors. When converted to PixelBlocks (via my own preferences mind you) the converted sprite looses about 6 colors, being made up of 11 colors in total.
(changes in color had to be made to conform to the pallet available from PixelBlocks)
Something like a sprite from Lords of Thunder would be more difficult to create with PixelBlocks (with the limited 20 color pallet) due to the shades they use in the game...but again with some pallet changes it can be done.
The down side is that well, this isn't cheap. The "Bonk Smiley" alone cost $30.34 (3 colors+tax+ground shipping). The Soldier Blade ship will cost me an additional $73.67 (with tax & shipping).