I would agree with Vangoghfan on this one. Given the fact that As You Like It has been dissected and re-dissected over time, you may want to look at it through a new lens (Darwinian or Naturalistic). The hardest thing about writing about Shakespeare is the fact that it has been examined so many times. My suggestion would be to find something novel to the play.
There are numerous ways of approaching this topic in terms of themes or topics, although finding anything really original to say might be difficult since this play has been written about so much. You might want to look at the play in terms of "ecocriticism," which is a relatively new approach to studying literature; you might even want to look at it from a Darwinian perspective, which is another relatively new way of looking at literature. Your best bet for doing something original might be to focus on one short scene and discussing how it fits into the play as a whole and how it is effectively written in its use of various literary techniques.
thank you everyone.....