I used Cruise Critic Reviews as a guide and most reviews seemed to be ok about the Fantasy till I went recently. The two days at sea you have very limited options if you are a young couple looking for some fun. Majority of the options that sound appealing would require you to pay, such as the SPA or the Casino. The only free option on the cruise is the pool or Jacuzzi and ONLY IF it isn't crowded or kids are jumping in and out of it. They do have an adult section that consist of A Jacuzzi and several beach chairs, GOOD LUCK WITH THAT. I went on 3 different occasions to see if there was room and hold and behold NO ROOM AT ALL. The dining experience in the 'Celebration Room' was a 7 out of 10. Mostly crowded and if you are a couple, get ready to share a table with other folks. Room service is convenient to use at all times of the day and the service is pretty quick. Breakfast is buffet style and can be a little bit of a pain to stand on line. I do suggest not to waste your money/time on taking the zillion photo-op option they have throughout the ship. For one picture (10x14) get ready to pay $23. You can very easily tour the ship yourself within 1-2hrs. ARRIVE early to embark on this ship as it can take forever to get on the ship. Even though they say the getting on the ship process is between 12-2pm, they actually started the process at 10:30am. Plus by the time you get in, they do have the buffet lunch ready so you can eat as soon as you get in. As a young couple, the only things I enjoyed was the Comedy Show at 'The Punchliner', 'The Game of Love' (interactive game made for married couples), the Jacuzzi(if there is room), the Ocean view throughout the time at sea, the two plays performed at the Universal Lounge, The Junkanno (aka Taino Beach) & Port Lucayana (for shopping bargaining is the best route to save some money) at Freeport, Bahama, and the British Colonial Hotel ($55/person ONLY accept credit cards) at Nassau, Bahama. Nassau is a port that is completely catered to tourist so expect to pay a lot more for your souvenirs when shopping. If you can afford the tours through the shore excursions, that may be a plus for a better adventure. If you only care for shopping & beach, you are best to take the taxi available by Freeport which will take you to Junkanno Beach (aka Taino Beach) and will pick up and drop you to the shopping area of Port Lucayana(will pick up & drop off to main port where the ship is every hour). Freeport is an industrial location so there is very little sightseeing available near the cruise port itself. The Taxi driver may also give tons of small facts as he is driving but mostly sad facts (burned down or closed down resorts near the cruise port).
Food is ok at the beach, and there is no other places to eat at near this beach, and there are only bathrooms available to change in. As for Nassau, everything is walking distance. It is definitely worth $55/person to go to the British Colonial(owned by Hilton) which has it's own access to the beach (no kids in sight) and only a 5-10min. walking distance from where the ship is. At Freeport, taxi ride & access to Junkanno Beach & Port Lucayana for two ppl cost $55 in TOTAL but you will find tons of kids and a lot of people from the cruise there whereas in Nassau, paid $115 in total just to get on the beach but it was clean and secluded. You will see many other couples there, which is great. I hope my review could be some help to you. I do suggest you do your research of places to see and prices. From what I understand, majority of Carnival ships are made for families so next time I will try Celebrity Cruises or Norwegian.
PS When leaving the cruise the last day, it is a very confusing process especially if your room is towards the back of the ship.
PSS The first day we got there the interior room had the twin beds in bunk bed form and after waiting an hour our steward corrected it so the twin beds were next to one another to equal a king size bed.This incident was a bit annoying especially since we were tired and wanted to sleep.