Standup comedian Jo Firestone loves puns. The Brooklyn-based comic adores wordplay so much that she co-created an Apples to Apples-style card game called Punderdome: A Card Game for Pun Lovers. Onstage, the former “The Tonight Show Starring Jimmy Fallon” writer performs with awkward, nervous energy. This often enhances her deadpan punch lines. And even though she sounds like she’s about to cry, as she tells audiences, she’s actually about to laugh. Firestone performs on Friday and Saturday, September 27 and 28, at the Vermont Comedy Club in Burlington.