We have been to Mission Beach a couple of times so far during our stay here. The beach was nice, with soft sand and the waves were just the right size for us. There are other things to do around here as well. There was a fun looking amusement park at the beach called Belmont Park. It had a roller coaster and a few small rides, an Escapology, and an arcade and games. Some of it was open, but it seemed like a lot of it was closed while we were there. It looked like it would be a really fun place when it was all open.
Next to Belmont Park, there was a street (Ventura Pl.) which ended in a cul-de-sac right next to the beach. There was a parking lot, as well as several food and souvenir shops along this short street. When we were done walking the beach, we rinsed our feet off in the outdoor showers. As we were sitting down to put our shoes back on, a group of motorcycles came in and lined up along the end of the street. A few of them started doing tricks in the center of the cul-de-sac. It was really loud, but the kids got a kick out of it. There was even one guy on a bicycle, who jumped in to do a trick as well! (Video link) Once a few of them had preformed, they drove off.
It was just a random pop-up crazy experience.