1- he will definitely like villageo specially virgin mega store and the cinema and don't forget to take him to the amusement park in there.
2- go and watch the crazy driving in dune sands near sealine beach resort in Umsaeed.
3- hire a boat from Cornish and make a sea journey.
4- if he likes the history and cultural activities u can visit the museum and katara.
5- have lunch / dinner in the torch rotating restaurant.
if u have more time u can think about additional activities