Use the scroll bar to see the entirety of this map.
Starting from the right side of the stage, clear away the looping enemies that you encounter as you begin to cross the bridge. Further along, you will encounter heat seeking missiles. Destroy them as you reach the end of the bridge. Stronger but slower looping enemies occupy the ground between the grass ledges. Heat seeking missiles will appear as you continue heading to the left. When you reach the base of the tower, several sentry cannons will be positioned on the ledges. Clear them away before advancing to the top.
Once you reach the screen above, you must hop up the platforms to reach the door at the top of the tower. Along the way, you'll encounter more cannons. Near the top of the tower are two floating enemies that will lob bullets across the screen at you. Before you head inside the door, be sure to load up on Health.
When you first enter the room, you'll see your girlfriend Mary on the left. Bang speaks to her, but she'll ask him to surrender. When he question her, she begins to shoot Bang. You'll have no choice but to shoot back until she is destroyed. The black Pandar will ridicule you for shooting your girlfriend, but Bang will reveal that he knew she was a fake all along. Bang also thinks Pandar might have two medallions, but they reveal they actually have none. When Bang asks how to get to Guycott's fortress, Pandar reveals that you have to dive through the well on Route 15.
Then Pandar will begin to attack. In their first phase, the separate black and white Pandars remain on top of their platforms and lob bullets at you. You need to hit them enough times to change their strategy. To do that, you have some options. You could put on Power Boots so that you can jump higher, but a better strategy would be to use the Rolling Star weapon. This weapon moves with you whenever you jump, so you can fire it off and jump up, and the bullet will likely strike one or both of the Pandars. When it has taken enough damage it jumps to the ground and combines into one being.
In the second phase, Pandar simply remains in the center of the room. Whenever it takes some damage, it spawns multiple heads in a tower, and then all of the heads float off in your direction. You'll need to shoot the ones which are most in danger of touching you and doing damage. Once again, the Rolling Star helps tremendously. If you stay on either far side of the room and shoot twice at Pandar, the first shot will hit him, causing him to spawn his heads, and the second shot will fly up and remove a number of those heads before they fly toward you. It will only take a few shots from Rolling Star to defeat Pandar. Unfortunately, you gain very little from the experience, other than a full meter of health. At that point, you're only option is to return the the right exit.