To make less preparation for you, because you should have fun too, make the Mardi Gras party a potluck. Assign each guest one or two dishes to bring, and save the specialty items for yourself. That way you can include special treats, and the guests won't feel too stressed by what to bring.
Potlucks work best if you give people a general idea of what to bring. You can say something like: Suzy is bring roast beef, and Mary is bringing salad, so why don't you bring a dessert? That way the guests are guided to a type of dish, but not pressured into an exact item (unless you know that Suzy makes the best chili in the neighborhood, then you should ask Suzy if she will make her world famous chili). Potlucks are also good because it spreads the costs of the Mardi Gras party around, and no one has to spend a lot of money.