This is it. The final battle. For real this time. You'll be equipped with the Great Sacred Treasure regardless of your gear, but this is alright; the Great Sacred Treasure is the game's best weapon, with lots of power, homing projectiles, and a high rate of fire. You'll be able to breeze through the initial few waves of enemies without much trouble, but don't get clumsy; you'll need every bit of health you have to take on Hades.
Final Boss: Hades
Hades starts with a quick paced section where he shields himself with his cape. Dodge his projectiles while waiting for him to expose parts of his body. When he makes a tornado, there's not much you can do. Just keep on trying to dodge. Then, Hades will run after the player, creating another "shoot n' dodge segment." Try circling around the screen to avoid being hit.
The next section involves chasing after Hades while he's flying through the air. Destroy the turrets on parts of his body to progress. When he creates shields, blast through them. Be sure to destroy his less turrets such as his "face guns" before going after the shadowy blob on his back. Otherwise, you'll have to deal with a LOT of enemy fire.
After getting a couple of Recovery Orbs, it's time for the third stage. Hades will once again be covered in weapons, and it'll be your job to destroy them. When he sticks out his hands to attack, shoot the center of his palms to destroy his offensive prowess and gravity manipulation abilities. The last part consists of a number of turrets on his chest, including a centerpiece that you'll need to destroy. It is a priority, but once again feel free to take out a few of its neighbors first to make surviving easier.
The fourth part of the Final battle puts a twist on the formula. Hades will shoot purple and blue energy shots. The blue ones can be destroyed by firing at them, but doing this to the purple shots will only hurt you. Aiming is more important than ever. Meanwhile, focus your fire on the gem in the center of Hades's body. Be sure to keep this up and dodge his shields, and this part is simple other than the precise aiming required.
When Pit falls to the ground, use the analog nub to guide him onto the proper spot, which is highlighted below. After that comes a very unusual segment. Your goal will be to keep the reticule on Hades despite a mysterious force pushing it away. You'll have to constantly flick the stylus in the right direction. Try aiming for the gem in Hades's stomach. Keep the target on hades to fill the bar at the top. However you have to hurry. If you don't fill the gauge fast enough, he will shoot you with a huge deadly beam, resulting in an instant game over.
The final section is all about dodging. Hades will use three constant beams of energy to attack you. The ones coming from his hands are fairly stable, but the one from his face will follow you around. DO NOT ATTACK UNTIL FULLY CHARGED! Otherwise, you'll have to start over again. Once charged fire.
Congrats. You beat the game!