Kingdom Hearts 2 hints -PS2

Unlockables:

Cerberus Cup	Clear Agrabah, Halloween, and Pride Land for the first time
Goddess of Fate Cup	Clear previous cups and beat the first fight with Xemnas
Pain and Panic Cup	Clear Disney Castle for the first time
Paradox Cups: Cerberus Cup	Except Final Form, Form levels must be at Lv. 5 and must unlock Paradox Cup: Pain and Panic
Paradox Cups: Hades Cup	Clear all the previous cups, clear Space Paranoids for the second time, and have ALL forms and summons at Lv. 7
Paradox Cups: Pain and Panic	Clear all the previous cups
Paradox Cups: Titan Cup	Summon level should be at Lv. 5 and have the Paradox: Cup Pain and Panic unlock
Titan Cup	Clear Olympus Coliseum for the second time

Special Models

These are special models of gummi ships you can get by doing the certain gummi missions and getting S ranked on them.

Cactuar	S-Rank: Broken Highway Mission 2
Cait Sith	S-Rank: Sunlight Storm Mission 2
Chocobo	S-Rank: Ancient Highway Mission 2
Fenrir	S-Rank: Assault of the Dreadnought Mission 2
Highwind Model	S-Rank: Asteroid Sweep Mission 2
Kingdom Model	S-Rank: Asteroid Sweep Mission 2
Mandragora	S-Rank: Floating Island Mission 2
Moogle	S-Rank: Splash Island Mission 2
Mushroom Model	S-Rank: Assault of the Dreadnought Mission 1
PuPu	S-Rank: Stardust Sweep Mission 2
Secret Model	S-Rank: Assault of the Dreadnought Mission 3
Tonberry	S-Rank: Phantom Storm Mission 2

Summons

Where to get each summon:

Chicken Little	In the 100 Acre Wood, after the world's second cutscene.
Genie	Defeat Volcano Lord and Blizzard Lord
Peter Pan	In the ship graveyard in the second visit to Port Royal.
Stitch	In the hallway to the computer room in Hollow Bastion, after you get Master Form.

Torn Pages

Torn Pages are required to play and complete all of 100 Acre Woods.

Torn Page 1	In the Disney Castle's Library.
Torn Page 2	In the Pride Lands at the Oasis
Torn Page 3	In Hallow Bastion at the Crystal Fissure
Torn Page 4	At the Land of the Dragons in the Throne Room
Torn Page 5	At Agrabah at the Tower

Instant Max Drive

If you want you drive bar maxed, all you have to do, is, Go to the Underworld tournament. Talk to Panic, after talking to him, A screen of all Tournaments pop up.

Go to any one, and once you enter the first battle, Your Drive Bar will be completely filled. Pause, and select quit. When you leave, your bar is still full.

This will help you level up forms and summons quicker.

Also, if you return to the world map while in a drive form you will have a full drive gauge.

Quick Summon/Form Levelling

In Space Paranoids, just use any form or summon, and let the form/summon meter count down until it's almost gone. Then, immediately board the Solar Sailer. Your form/summon will be cancelled, but your drive gauge will be returned to its original state. Ride the Solar Sailer, then use the form/summon again. After the ride is over, head back and all of the enemies will return. Repeat until forms and summons are maxed. Obviously, this will not work for Final Form, since there aren't any Nobodies in Space Paranoids, but the other forms and the summons can be levelled freely, without any pesky drive-gauge refilling. It's possible that this trick works in other areas, too, but I have not explored it (the Black Pearl is an idea though).

Also, to level summons specifically, the experience counter seems to increment when the summon meter ticks down a notch. If your timing is good, try to kill enemies with drive orbs right when the meter is going to drop a level. If you can keep the meter almost full as you collect the orbs, you can make it oscillate between two numbers, netting extra experience for your summons. With this, you can get over 30 exp every time you use a summon.