Beat Kingdom Hearts 2 on expert.
EDIT by Appleness:
Lolness, I'm pretty sure he/she means the game Birth by Sleep's ending. Not the trailer for Birth by Sleep. Oh yeah and I just needed to point out, there's not such thing as "expert" on Kingdom Hearts II -.-"
Okay, anyway, on to the answer xD You can unlock the secret ending be either completing each of the characters episodes on Proud or Critical mode, or by 100%ing each characters "reports" section.
If you play on Normal Difficulty, do the following to unlock the cutscene Another Side, Another Story for Kingdom Hearts I:
Once you're done with the above, head to Final Rest in End of the World. Head through the tall white door to fight Ansem several times. After you beat him the last time, a cutscene of two guys confronting each other about Sora will eventually roll.
If you're on Expert Difficulty, you only need to seal every Keyhole to unlock the video.
Unlock a new gateway- you must complete the story line in that world you can skip agrabah or Halloween town the 1st try and go on right to pride lands but u will have to go back and do it.
Unclock synthis items- u will need to find all the treasers they contain rare items and synthis recipes also equips all collection items with friends so enemys drop more items
Unlock Poohs book- find all the missing pages (located in big chests) one is located in hallow bastion in the crystal cavern also one is in the underworld right in front of hatties room i think.
Unlock final form- don't do the underworld retry transform stuff. The quickest way is it find a nobody and transform literally right next to it if it doesn't work retry it but get closer. Your clothes will be white and you will be floating.
Unlock anti form- you have to use drive alot (not final form). After a while you will have full anti points (no way to tell how many u have) but when u use a form u will turn into a sora sized heartless with great speed and attacks (no keyblade) U cannot heal either so stay alive if u r low revert or run away!!
Gliding- you have to have lvl 2 final to get glide lvl 5 final gets u lvl 2 glide lvl 7 final gets u lvl 3 glide. to check your status click the menu go to status go to final it will tell u experience(how many u have to lvl up) and next lvl(how many nobodies u have to kill).
How to super jump- every 2 lvl 4 valor u get a higher jump the highest in lvl 3 jump i think
Max ur gauge quicker- have enough gauge to transform then go to a save spot and leave the world ur gauge will be maxed up to the highest lvl u have.
Gauges- you can get up to 7 gauges without using cheats if u have only six you have to go fight sephiroth (optional boss). Go to hollow bastion/radient garden then go to the save spot crystal cavern (if u don't have it just go to where u had to beat the 1,000 heartless)
Characters- need game shark and go to YouTube 4 free cheat codes in sted of giving your info (they do work and its legal)
You must earn 20 trophies to unlock the secret ending video.
Yes there is a secret. once you've found all the dalmation puppies you unlock a secret ending.
not that i know of
Get 100% complete on all 3 stories
No theres alot more
There is no Poseidon Kingdom. There's Atlantica, the Little Mermaid's world, but like all worlds in Kingdom Hearts, it's opened just by making regular progress in the game. There are no secret worlds in KH, just secret endings.
Common sence, you gotta work a little harder for better things.
Advance the storyline
I wish it was but unfortunately NO
Through merlin's house no the waterway is behind the bars in the alley way to get there beat deep jungle to unlock red trinity
Nope. Not even in Kingdom Hearts 3. However you can unlock his Dissidia costume in Kingdom Hearts Mobile. And theres at least one more Kingdom Hearts game coming out-so we Zidane Tribal lovers have hope. <3
Unfortunatly, you can't.