I was just on the Explorer last month and had a great time!!! I don't have any kids but I did notice some of the teens seemed a bit bored in the evening. Some of them were taking do not disturb signs and breakfast orders off of peoples doors, I guess out of boredom.
The main pool area seemed the place to be. Always lots of activities, bands, contests, etc. The sports area is a lot of fun. Rock climbing,rollerblading,mini golf,ping pong, soccer, basket ball and more. Fun for kids of all ages!
If you have half as much fun as I did you will be ready for your next cruise before you disembark.
Enjoy your adventure and if you have any questions I will do my best to answer.
Carnival Victory, 2003
Carnival Victory, 2004
RCI Explorer of the Seas, 2009