Great Thing is a mechanical sperm whale, and it has three attack phases, all of which are deadly, especially if you are ill equipped.
After it's approach, it will deploy a few subvessels that occasionally attack forward, and will cycle through the turrets attached to the main body:
The Center turret will rapidly fire lasers.
The upper turret will shoot a continuous beam. As it enters position, move to the top-left corner, and dodge by moving slowly down then to the right. The laser is a candidate for a bomb if it pins you down.
The front turret will shoot laser vollies, that will make a turn at a 90-degree angle.
Great Thing will move down. The back turret launches suppressing fire, while another turret deploys slow moving seekers.
After firing a shot at the ground, Great Thing may change it's attack when if it took enough damage. When it does, it will begin with launching drill-shaped missiles. In addition, it may start production of rotating cubes on higher difficulties.
Drill-shaped missiles will launch forward.
A long volley of homing lasers, most easily dodged if hanging around the bottom-left corner.
It will fly to the top-right, and fire a large array of bullets, and also drops fire support as well.
When critical, it will proceed with its final pattern. While experienced players can defeat it before it shoots lightning, this requires you to collect and retain powerups to the maximum level.
It will fly slowly towards the silver hawk, and launch a large number of missiles. Try to remain on the left as much as possible, then circle around the tail before it moves back to the right.
It shoots lightning that slowly advances. Cross when it's half-way through the shots, but watch for the seekers it also launches.
It launches a set of five homing lasers.
When it is defeated, you will receive any end-game bonuses, and get to watch the ending.
