There are many places in Kuwait that have Beach Activities here are some Places.
*Beach Volley Ball
Next to al Sharq Mall there are many nets for groups wishing to play.
In the Hilton resort all beach activites are found. There is a small price to pay for people who arent staying at the hotel.. Im not sure of the price.
You can also rent Jetskis in most places near the beach
Messila Beach (There is also a waterpark which is nice)
Painball Kuwait field is a large area, around 1/4 acre.
large bunkers, foxholes, and 4 castles/buildings.
They offer coveralls and chest protectors, and it's a shame I didn't get to try paintball yet.