The levels are almost always according to the same protocol. First a phase of appearance, where leaders, the "Galagas", arise followed by a formation of small insects they abandon on the playground after performing one or two flutter. Then a grouping phase where the army of insects aligns in tight ranks at the top of the screen, in the manner of the enemies of Space Invaders. Finally, the attack phase where creatures progressively go on the offensive. As the battle progresses, "Galagas" bring back reinforcements and usually end up joining the fight.