Axelay/Stage 4

The fourth stage is in an underwater cave.

Boss
The enemy starts at the top of the area. The cavern will shake for a several seconds, causing rocks to drop fro the ceiling, before the boss itself drops.

There are three attacks
 * A lightning attack from the upper-left extension. When you see or hear the purple glow, you should move to avoid being hit.
 * It will release enemies from the bottom, which will fly around in the water.
 * When low on health, it will shoot additional shots from the blue spots above and below the core.

It is vulnerable to attack on the front, by hitting the red core.