It's probably one of the best spots to chill out on the beach with friends and family. It's the closest beach stretch for those living in Colombo. There are a few other beach restaurants next to this which are pretty good as well.
Good vibe, you can take your booze since they don't have a liquor license (but they may charge corkage), good selection of food (especially the sea food section) and it's only about 20 mins from the center of Colombo.
Make a reservation before you go so that you can get a good table right out on the beach.