I would say temper your expectations.
As was mentioned it has a serious fanbase -- a release of a handheld effort would usually see the hacking sections here flooded just like pokemon would when the game is out in a month.
I have tried multiple games, handheld and console. Never got it to click and struggle to even understand why. The controls are awful (the late game air move stuff is marginal at best as an improvement), camera worse (even bad by PS2 standards), story absolutely nothing to write home about (imagine any generic Square-Exix plot but made even sillier by dint of having to drip feed a few characters and locations from Disney and Square titles).
Also the keyblade is a stupid idea.
"but but Disney and Square (Enix) in one game". Meh, don't care about Disney and not like Square have done anything for me lately. For the most part feels like a fan mashup game or silly ROM hack. Even the modern worn out family guy-simpsons-futurama parodies/jabs at each other get more of a smile.
"but this was a game of my childhood". I am sorry your childhood was filled with awful games for this to be a stand out one.
Anyway I have probably just uncorked a bottle of pure flamebait. Really don't go into this expecting some ageing masterpiece as much as post 16 bit Disney cash in game.