Royal Caribbean International’s Symphony of the Seas edges out Harmony of the Seas as the world’s largest cruise ship, and it’s packed with even more experiences to entice families and millennials.

Symphony measures 228,081 gross tons, compared to Harmony’s 226,963 gross tons. It can carry up to 6,680 passengers.

Most of them are travelling as families, and a sizable percentage will be millennials, according to Michael Bayley, president and CEO of Royal Caribbean International. He said a Gallup Poll ranked Royal Caribbean as the No. 1 cruise line for millennials.

Since millennials crave experiences, the bigger the ship, the more activities and variety it can offer, Bayley said. Plus, Royal Caribbean puts a lot of energy into its marketing, with a heavy focus on digital advertising and action-packed videos in online communications.

The Ultimate Family Suite

Spread across 1,346 square feet on two levels, this one-of-a-kind (for now) suite was designed to please all ages. Extensive market research uncovered the most desired elements of a dream home at sea for kids, teens and parents, and bundled them into one fabulous space.

The Ultimate Family Suite is outfitted with a bright orange in-room slide, a cinema with an 85-inch HD TV and a popcorn machine, a floor-to-ceiling LEGO wall and other fun, whimsical features. The 212-square-foot balcony has table tennis, a climbing structure and full-sized whirlpool.

The suite sleeps eight, has three bathrooms and seven televisions.

Laura Hodges, vice president of guest experience for Royal Caribbean, said an important selling point for parents is that the suite is so cool teens will want to hang out with them. “It creates family bonding in an unforced way,” she said.

Pricing for the suite is based on demand/seasonality and averages $45,000 to $80,000 per week, including the services of a Royal Genie, a butler of sorts who strives to make all wishes come true.

A Better Boardwalk

On other Oasis-class ships, the Boardwalk appeals mainly to children, with its carousel, Johnny Rockets burger joint and hot dog stand. Aboard Symphony, this neighbourhood has “come alive,” according to Vicki Freed, senior vice president-sales, trade support and service. “It was a kids’ zone. We wanted to expand it into a whole family zone,” she said.

So now there’s also the family-friendly Playmakers Sports Bar & Arcade, with 31 big-screen TVs, arcade games and bar food like burgers and fries to go with the craft beers and cocktails. And, just across the way, the new Sugar Beach sells ice cream and candy.

More Casual Dining Choices

Besides Playmakers, Symphony has two other new casual dining spots. The seafood restaurant Hooked is found in the upper level of the Solarium. Hooked serves fare like lobster rolls, crab claws, oysters shucked to order and the signature “Messy Fish Sandwich.”

For fast food Mexican style in the Pool and Sports Zone, El Loco Fresh offers tacos, quesadillas, nachos and burritos at a counter with serve-yourself salsas and toppings.

Fabulous Shows

In the Royal Theater, Broadway hit “Hairspray” is having a return run for Royal Caribbean, along with the new “Flight: Dare to Dream,” that starts with a flight to Mars and goes back to the Wright Brothers, with a 22-foot aeroplane that actually flies in the show.

Studio B’s spectacular new “1977” ice skating extravaganza starts in a dazzling way: with 48 drones buzzing in a choreographed routine. It continues with incredible projections on a high-definition screen under the ice, snow falling and Olympics-caliber skaters.

The AquaTheater’s new show “AquaNation” features daring stunts like high-divers and tightrope walking.

Adventure Ocean Youth Programming

Symphony has Royal Caribbean’s youth program and dedicated spaces for ages 3 to 17 in four distinct age groups, plus Royal Babies (ages 6-18 months) and Royal Tots (18-36 months).

Thrills and Chill

New on Symphony, the Studio B ice rink converts into a glow-in-the-dark laser challenge, “Battle for Planet Z.” Plus, the ship reprises Royal Caribbean action thrills like The Ultimate Abyss slide that plunges nearly 100 feet, The Perfect Storm trio of water slides, a pair of FlowRiders for surfing, a zip line over the Boardwalk and two rock-climbing walls. There’s an escape room challenge, too.

Younger kids can have fun with the spray jets and dump bucket at Splashaway Bay.

There are also places to chill, like the quiet, adults-only Solarium with its dipping pool and the family-friendly mini-golf course.