Mine was a port-intensive cruise with only one full day at sea (the last). The cruise director's staff are called "animators," and so they are. They must liven things up in five or six languages, and they succeed admirably.
There are few planned activities, and rarely are two scheduled to happen concurrently. More often than not, there's time between activities. If you don't want to miss anything, you won't.
There are competitions like ring toss, passing a hula hoop from one person to the next while holding hands, and kicking shoes into a wastebasket affixed to a higher deck. For the more sophisticated passengers, there are group dance lessons. There are also trivia quizzes (quite a feat, given the languages spoken). Each language has its own host.
Each evening there was a show in the Opera Theatre. It was given twice -- an earlier pre-dinner show for the late seating, and a later post-dinner show for the early seating. In order to appeal to the greatest number of people, the acts were mostly visual. There is a resident song and dance troupe, and there are other entertainers who rotate among Costa's fleet. On my cruise there were several singers, a magician and a contortionist(!). The singers and dancers performed enthusiastically, but the sound level was deafening.
In the Tango Lounge each evening, a talented Macedonian couple played musical instruments and sang to a click track. There was a pianist who played cocktail music in the Piazza. There's jackpot Bingo daily, though, alas, no art auction.
Cocktails and other beverages are served at the Capri Bar (midships pool area); Grand Bar; Juliet Bar; Terrazza Bar; Tango Ballroom; Opera Bar; and Diva Club. Prices are fair for mixed drinks (5 to 6 euros [$6 to $7.20]). Italian drinks like Grappa and Limoncello are available, and all bars serve Lavazza cappuccino and espresso, regular and decaf, for a nominal charge (under $2). Children (and adults not too proud to ask for a "children's card") can have a card that entitles them to 20 juices or soft drinks (but not mineral water) at a discount. As it is an Italian ship, Costa Romantica's wine list runs heavily to Italian wines. While a few wines are expensive, there are many to choose from at between 17 and 19 euros ($18.40 to 20.80) per bottle. Half liter carafes of wine are available at 8 euros ($9.60), and wines by the glass for 4.50 euros ($5.40).
The video arcades contain a large number of games that cost .40 euros ($.48). There are also shove ha'penny and hockey games that are free. The Excelsior Casino has one dice table, three blackjack tables (minimum bet: 3 euros [$3.60]), one Caribbean stud and one Caribbean draw table, roulette and .10, .20, and .50 euro slot machines. The casino is quite small and not crowded on European sailings. The Tango Ballroom is an aft-facing lounge with tiered seating. This is the ship's alternative show lounge, which offers musical acts and a small floor for ballroom dancing. There is a bar (with bar stools).
Are religious services "entertainment?" Three religions had major observances the week I was onboard. Muslims observed Mawlid an Nabi, the Prophet Mohammed's birthday. Despite there being Muslim passengers and crew onboard, there was no mention of the holiday in "Today." Jews observed Passover. There was also no mention of the holiday in "Today." A nice touch would have been an offer on the part of the ship's company to provide Jewish passengers with the necessary foods for a Seder and to offer space for one. Christians observed Holy Week and celebrated Easter. The ship's resident Roman Catholic priest offered the customary services, but he apologized for not speaking French, English or German and told the Spaniards they could understand Italian (which I'm sure came as news to them). The ship's accommodation of religious observance was, given the particular week of my cruise, inadequate. The ship was decorated with white crepe paper bells and Styrofoam cutouts of doves -- which were intended to be Easter decorations -- and each cabin door was decorated with a crepe paper egg. On Easter Eve passengers were given large Lindt chocolate Easter eggs in their cabin.