This turned into an essay …
We went to castillo last year with our 3 children. We chose castillo because of the room configuration - there was a separate bedroom that my husband I and shared then and then 2 open plan sleeping areas for the children, one sofa bed and 2 single beds pushed together with wardrobes. It was really open plan - the kitchenette and bathroom sink were all in the same space as the sleeping areas with small separate toilet and shower cubicles. The room was spacious and suited us, I think the bathroom situation would be more challenging if our children were older (my oldest was 8 when we went). We had a little balcony and the area was quiet.
Food is fairly standard. We went to Barcelo Lanzarote active a few years ago and food was similar so would imagine Castillo is the same as Jandia. I don’t think the snack bar was as good at Castillo but there was still options.
The pools at Castillo are all saltwater and our kids liked them. There are 2 in the main bit then a hidden one by the kids club at Castillo which is worth checking out. There was also entertainment around the pool every day. You can also use the facilities at Barcelo Fuerteventura Mar which is a 5 minute walk - it’s a lot busier on that side but their main pool is heated! There’s also some à la carte restaurants on that side and mini golf (additional cost) and the spa.
Our kids loved the mini disco but we didn’t really go to any of the later entertainment so can’t comment on that. The staff were really lovely, our kids took part in some of the activities like sand painting and the staff were great with them. We did use the kids club twice but mixed reviews on that. The one at Castillo has a splash pad which our kids loved and they did an activity with the person running the club but the one at Mar is just a big exposed play park. My youngest went there on her own for an hour and apart from getting her face painted they didn’t really interact with her. She was a bit sad when I picked her up. We did go at end of season so maybe earlier on it would have been busier and more kids to play with.
Theres a strip of shops and bars just past Fuerteventura Mar so that gave us a small excursion shopping for souvenirs. We didn’t really go to the beach, it’s very exposed. There are loungers and umbrellas on the beach you can pay for.
Overall we had a good time. It’s close to the airport too. We didn’t do too much other than hang around the pool so I was a bit over it by the end of the week but Castillo delivered everything we wanted. You can hire boats / pedalos etc from a private company next to Castillo on the beach and there’s an inflatable obstacle course on the sea that my son went on and enjoyed.
Enjoy whatever you decide to do!