I'm a bit more with ter-o about keeping this constructive.
with that said, I do think you should apply the 1 critique they gave you that'd resolve everything. Draw a different angle, expression, try even different proportions. You see, if you make it too close to the original, all of the solutions are already mapped out for you and it would be WAY too tempting to just take those solutions... its actually extremely hard NOT to.
take for instance my Kenneth Fejer study..
http://pixeljoint.com/pixelart/13537.htmthat particular screenshot wasn't trying to imitate one of his own
conceptually - but it was taking into account all of his
style and applying it to a new concept. Things such as his abundant use of the 1px colored outline, subtle use of AA, and his pastel color choices.
willfaulds thread is also a great example of how to take a style without replicating the original.
but again, the easiest way to do this is to apply the style to something completely different than the original. Whether that means a different angle, different expression, different lighting, or maybe even a different subject - it all helps.
-Dan