Yes, Twelfth Night is a festive holiday play—its title, in fact, refers to the twelfth night of the Christmas season, the day before Epiphany, which celebrates when the Magi brought gifts to the infant Jesus. Twelfth Night was often celebrated in Shakespeare's day with the drinking of wassail, a hot mulled cider, parties, and "merriments."
Shakespeare's play captures the zany, upside down feeling of a festive occasion. Genders bend with Viola impersonating a man by disguising herself as Cesario, and humor revolves around Malvolio, the steward trying to cross class lines to woo Olivia. There's quite a lot of love, obstacles to love, mistaken identity, mix-ups, and word play in this madcap comedy. Sir Toby Belch and Sir Andrew Aguecheek provide comic relief along with Malvolio, and the play comments on the lunacy of love. But perhaps the festive spirit is captured best in the appropriately named Feste's carpe diem [seize the day] song about love:
"What is love? 'Tis not hereafter;
Present mirth hath present laughter,
What's to come is still unsure.
In delay there lies no plenty,
Then come kiss me sweet and twenty.
Youth's a stuff will not endure."
If you are looking for an entertaining romantic comedy to top off Christmas festivities, this "enjoy the moment" play would be a fine choice.