You have to play the levels in order. You can only select to play a certain level if you've already completed it in the campaign, either solo, or with a friend.
Buy them. As you play beat more and more levels ypu unlock the planes then buy them.
if it is on the multipayer you need to have halo waypoint and a certain achievement. if not i dont know
go on stick page
levels of what?!
You unlock levels one at a time. You unlock the next one after you beat the previous one.
impossible. you have to do levels to unlock miis.
rank up
unlock all levels zuma revenge
You go to Combat Training.
pass the game
unlocking ninja
There are 65 multiple player levels to unlock