Should I complain to my neighbor about their kid playing basketball?
Why would you complain about this?
I thought they should know that it bothered me
There is nothing wrong with a child playing sports, even if this somehow annoys you. You shouldn't complain to people about their kids unless something is happening that could actually cause a real problem.
I didn't care what happened to the kid but I wanted to make them feel bad or some shit.
You have way too much free time on your hands. Unless this kid is causing trouble, then leave them alone. Stop butting into this kid's game of basketball and go do something productive with your day.