Story-related, can't be missed.
As soon as you start, the boss will be charging at you back and forth until he goes on the next bridge. Then he will be shooting missiles at you so keep an eye out on the ground for black dots and move away. After he's done the two red buttons will be green. The key is to keep an eye out for where his tank is, so if his tank is on the left you hit the left button. Now the tank will fly to the middle of the bridge where you are and the boss will pop out. Jump on his head to finish wave one.
For wave two he will go back on the bridge and shoot a purple missile out. Move away from the middle of the bridge because that missile will destroy it. He'll now charge at you again a few times and go back on the bridge to shoot more missiles, once he's done the buttons will go green . Press the button on the side he's on and he'll go flying back to the bridge and you'll need to jump on his head again.
Wave three is the challenging round since he will shoot out two purple missiles out to destroy the last two bridges. All you have left is the poles that are popping out. Just dodge everything you can until the buttons go green and once he fliess over jump on his head and it will be over.