See, that's kinda the problem with a sprite-based game engine, you need all the images beforehand, and thus, you need to draw all the animation frames out somehow. If you can do it right, though it's well worth it; Frankly, I miss the days of well-made sprite graphics in games... I mean, cel-shaded games are GOOD (so long as they're done right), but they ain't the good ol' days...

But anyhoo, with your pics... looks pretty good, I'd say. Except, you might want to make the arms and legs shorter. I think they're a bit long for the cartoony look you said you were after... Sure, bigger arms and such are good for cartoony, but too LONG doesn't work as well...