Dreams are clearly an essential part of this play, as is made clear by the dream-like magic that occurs in the wood. In particular, it is key to realise how they are explicitly associated with the chaotic events that occur in the forest and how they relate to the chaotic arena of human emotions, as characters fall in and out of love with each other and become transformed, if not in their affections, then in their physical appearance. In particular, you might want to analyse the response of characters when they "wake up" from their various "dreams" after leaving the forest. For example, Bottom famously in Act IV scene 1 delivers a speech that points towards the difficulties in quantifying and explaining dreams:
I have had a dream, past the wit of man to say what dream it was. Man is but an ass if he go about to expound this dream.
Ironically he refers to man being "an ass," which is of course something he has had recent experience of, which helps point towards the imprecise and nebulous nature of dreams.
Of course, the dreams that feature so heavily in the play are related to the work of the fairies and magic, that help distort time and make impossibilities possible. Magic and dreams are inextricably intertwined, and are crucial to the way that this play presents us with a sense of illusion and unreality. Consider how Puck ends the play in his final speech delivered directly to the audience:
If we shadows have offended,
Think but this, and all is mended,
That you have but slumbered here
While these visions did appear.
And this weak and idle theme,
No more yielding but a dream.
Puck says that if we have been offended by the play, we can pretent it is nothing more than a dream that can therefore be forgotten and dismissed. There is an element of ironic humour in this final speech, as Puck suggests that if we do not want to pay attention to the lessons the play has to offer regarding how love impacts us and can change our affections so quickly, we can, like the lovers, pretend it was just a dream and ignore such discomforting lessons.