As soon as you jump on the Cyborg Rider at the end of Area 1, your health meter will be slightly extended for the first time. Head through the exit in the upper right to begin Area 2.
You will first encounter a set of enemies who fly across the screen in a wave. As the first S capsule appears on the screen, an additional enemy floats along the bottom and tries to line up beneath you before firing. The first P capsule follows very shortly after that.
A set of enemies appear which break apart into four pieces like the bubbles in the flying section of Area 1. Short after that, another new type of ship appears. They fly straight across from left to right, slowing down to fire across the screen before speeding off. Stay near the top to avoid most of them.
When the second S capsule appears, a new threat will arrive. Two halves of a large head will assemble around a disc in the middle. Start firing on the center section of the face as quickly and early as possible if you want to try to destroy it. Otherwise, you can simply fly around and try to avoid it, but be aware that it moves very quickly to the left and somewhat slowly to the right, so you're safer on the right side of the screen.
By the time the face is fully assembled, the second P capsule will appear. Collect it to power up your weapons, adding an upward diagonal shot to your main guns. A variety of enemies will appear. By the time a third P capsule appears on the screen, a new enemy will appear from the left, travel a little beyond the middle of the screen, and then retreat to the left. You must destroy this enemy. If it is allowed to remain alive, it causes the screen to flash, doing damage to you.
The sky will dark, and the speed will start to increase. The background will disappear completely, and you will be flying through the dark. Platform will start to whiz by, while more of the exploding enemies appear from the right. Stay near the top right corner and do your best to avoid all of the fragments from the enemies. The platforms will stop and the boss will appear.
Jeliza resembles a giant face with a bandanna and a beard, He is vulnerable just about everywhere you can shoot him. His main weapon is a spread of three large fireballs which shoot out from around the nose. He has two secondary weapons, a spread of three smaller bullets that he will either fire from his head or from his chin.
There is one part of the screen that is fairly safe until Jeliza gets too close. You can park Apollo just below the height of the middle fireball. The lower fireball will pass below him. In the meantime, the spread of bullets should go around him as well. However, once Jeliza gets too close to you, you should head up or down to avoid getting hit until he backs up all the way and continues approaching you again. Return to this safe spot and continue your attack until Jeliza is defeated.