The play the mechanicals performed was ironically quite comical. It is ironic because, despite the poor title Quince chose for the play, "The Most Lamentable Comedy and Most Cruel Death of Pyramus and Thisby," the story of the legendary deaths of Pyramus and Thisby is a tragedy. The story is a tragedy because both the main characters die, showing us the characters' tragic flaws and how they are controlled by fate.
The mechanicals' performance of the play is, however, comical. It is comical because the prologue Quince delivers is nonsensical. One reason it is nonsensical is that he mixes up words, such as "the true beginning of our end" (V.i.118). He even gives contradictory statements, such as, "We do not come, as minding to content you, / Our true intent is. All for your delight" (120-121). This is a contradictory statement because on the one hand he says that they are not performing the play with the intention of pleasing, but on the other hand their intention is to delight their audience. A third reason why Quince's prologue is nonsensical and comical is that he places punctuation where it really does not belong, such as a period immediately following a verb in the line, "Our true intent is. All for your delight" (121).
A second reason why their intended tragedy is comical is that they make the choice to dress an actor as a wall rather than build a movable set. A final reason worth mentioning why their performance of the play is comical is that they decided to have an actor represent moonshine; but what is most hilarious about the description of moonshine is that for no known reason, moonshine has with him a bush and a dog, as we see in the comical lines:
All that I have to say is to tell you that the lanthorn is the moon; I, the man i'the moon; this thorn-bush, my thorn-bush; and this dog, my dog. (256-258)
We cannot really say that the play is a comedy because it does not have a happy ending. Comedies must have happy endings in order for them to be comedies. Hence, while the play is a tragedy, the mechanicals ironically make it a comical tragedy.