A cruise is my idea of hell, but I have a strange fascination with YouTube cruises.
I've learned a lot.
Different lines for different people. Disney is great for kids, Silversea better for adults and more luxury.
Itinerary - do you want more ports of more sea days? The Queen Mary crosses the Atlantic so is all sea days.
Is there somewhere you HAVE to see, if that port is dropped how will you feel?
Languages, Costa do announcements in 5 languages which some people find annoying.
Size of ship, some have room for thousands of people. If you are in a tender port then the priority to get ashore goes to people who have booked an excursion with the ship.
Things on the ship, do you like shows? Roller coasters? Pools? Type of dining? Talks / lectures?
Type of cruise, there are naked cruises, cruises dedicated to a type of music.
I think cruises can be fantastic holidays if you make the right choices.
Personally I don't like being on water, I'm not even keen on cross channel ferries.