Tactics and weaknesses
When the Great Commander combines for the first time, it will attack with lasers and metal weapons. When it combines, it will use six lasers to combat the player. Those turrets are also the weakness of this boss. They are really hard to hit, so have Nova Bombs and Twin Blaster Type B. Once they are destroyed, the Great Commander will retreat to the surface.
Mode Change: Robotic Mode
When the Great Commander approaches you a second time, the ships that comprise it will transform into a R.O.B-esque robot. It gains a new attack: iron balls will be thrown. In this mode, the Great Commander's weak spot is a square that opens on the bottom component. Once that is destroyed, the Great Commander will start flying around. The smallest component must be destroyed for it to be defeated completely.