ND, I would say for a game project it would be unwise to make a character move around that much just for a simple combo; I tried it once to a much lesser desgree than what you have there, and I ended up with massive design issues 
I would say what's really important is to keep in mind the range of the attack. You don't want to force the player to be right on top of the enemy in order to do any damage but you don't want him to have such long range that the game is a cakewalk, either.
I agree 100% that it would take more effort to design, but that's why 99% of bad games use a character that doesn't move. It's
boring. Even mario has a "ranged attack."
Also, my edit shows a
lot of motion (over the top to make a point about how static the sample is), and for some reason when i heard "combo" i thought "special move" (not regular attacks), so yeah, then it's quite overdone.
however, i do not agree that range makes games a cakewalk. in a still game, you can just stand still waving your hands - motion makes you
commit to the attack - there are decisions and consequences. the sample also has maybe 5 frames of falling at the end when the character is vulnerable - not repelling enemies. this adds layers to gameplay that make up the coding difference. you also need to think about where you land - Captain Falcon in smash bros is NOT a newb character. when all else fails, you can always balance by adding health to enemies and taking it from the player (which makes motion imperative).
if you've played them, compare fighting in Dark Cloud 1 to Dark Cloud 2 - the only major difference is the addition of the lunge and the backflip, but i think everyone would agree that the combat is more lively and engaging and not at all easier.
all that is academic though if you've chosen to keep a rigid box. i will keep the point though that the animation right now is really boring. my guy happens to advance, but all the kicking and turning can still be done without moving him forward much. I only broke his spine - but you can look at elbow and knee joints too - anything to add interest. if the player is bored with your silhouette he'll probably be bored by your final sprite.
at the very least, you need to do something about the hands. right now he attacks twice from right to left, which is just a big no-no. fighting always moves from the same location. if you attack to the right, you continue
from the right. same goes for left or center. when you don't you end up with mister doesn't-turn-his-shoulders-ever, and this is awkward and makes for weak-looking attacks. try this move of yours in person, swing your left arm across while keeping your right back, pause, and attack with your right. sooooooo awkward. next, try attacking with your left counter-clockwise and bringing the right hand with it passively, then striking back clockwise with the right (or, like my kung fu guy, do a 360 and continue the counter-clockwise motion). either of the second options will feel much better.
