The course of true love?
The centre of the plot is rather like a Roman comedy--with romantic trimmings. There are two young lovers, hindered in their love by the crusty old man, the senex*, and they plot to escape his tyranny.
But the second plot, the misdirected love of Demetrius and Helena, and the whole invention of a love-juice, is wholly new, and much more in the tradition of romantic comedy. Even in this one plot, Shakespeare has created different layers--Roman and romantic--in the recipe for comedy.
Like the lesser plot of Theseus and Hippolyta, the situation and character of the lovers draws attention to the traditional relationship between the sexes*.
Footnotes
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Senex
Latin for "old man." Click on the link "Roman comedy" for more.
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Gender and power issues
- Egeus claims absolute control over his daughter; would an
      Elizabethan audience have agreed?
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(Click on the link "Fathers and daughters" for more).
 - The relationship of Hermia and Lysander seems relatively
      well-balanced, but what of Helena's submission to Demetrius:
      "Use me but as your spaniel, spurn me, strike me . . ."
      (2.1.205)?
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(Click for more)
 
 - Egeus claims absolute control over his daughter; would an
      Elizabethan audience have agreed?