We went on a 3 night cruise to Barcelona and Marseilles, France on Costa. Overall the experience was not a bad one, but certainly one that if you are not Italian or even European can be a bit of an adjustment.
The ship was well cared for and was in the Greek God/Goddess theme. What this means is that I spent several times answering questions from my little one about "what is that" when she pointed to the naked men and women (Greek figures) throughout the ship. The decor was nice, the main area was nice and the cabins were extremely spacious and well maintained.
Bingo again was the highlight activity on the ship! We played each night. The shows were pretty good. We pretty much did our own thing for the most part. The cruise ship boasted about the kids activities and we took the youngest to the kids area and many times she was the only one. Many people on the cruise opted to have their children with them. My teenager didn't find anything interesting in the teen zone as again it appeared no one really hung out.
Barcelona is great but there was not enough time to do anything with the limited amount of time the cruise was docked in port. The sightseeing bus (with no stops) and then a quick walk through the shops is about all there is time for.
Spent an entire day here when it could've easily been a couple hours. Took the sight seeing bus around the city and spent the rest of the day eating and going through the shops. There was really nothing much else to do.