Getting back into sprites

[GrooveMan.exe]

The look you're going for reminds me a lot of this:
http://sdb.drshnaps.com/objects/2/1/Sprite/Gyamon.png
http://sdb.drshnaps.com/game.php?game=1&view=2

The sprites from this game do a very good job of balancing black outlines and shading with bold colours - and dynamic 'fighting' poses with reasonable balance (Though Gyamon's center of gravity is off because he's the 'crazy, unhinged' character). Take a look at 'em.