Well the first thing you should know is that You won't miss out on the story since the additional scenes are connected to the games after it and they are technically explained, however I do recommend watching them in youtube. I will give you a list,note that these features while long will not affect your understanding of the game's plot. May Contain spoilers They included additional scenes involving the Kingdom Hearts II secret ending.
Also indicated that battling Roxas will be possible, each member of Organization XIII can be challenged in a secret area of Hollow Bastion and fought independently of the storyline. Voice-acting on Final Mix was announced to be mostly in English, with Japanese subtitles, like Kingdom Hearts: Final Mix. Several new scenes, however, use Japanese voice-acting .
New features 1. Members of Organization XIII that were eliminated in Chain of Memories can be found and fought in the various worlds. They each use different fighting tactics from the ones they employed in Chain of Memories.
They include Vexen, Larxene, Marluxia, Lexaeus, and Zexion. 2. Zexion's weapon is revealed - a large book called a "lexicon", which he can use to trap his enemies in an alternate reality.
3. An area of Radiant Garden can be accessed that houses a simulation of battles with each member of Organization XIII. This is a separate feature from the secret battles with the Chain of Memories Organization members in that the simulation allows the player to repeat any battle with an Organization member as often as they like.
The simulation features highly powered-up Organization members, similar to the level bonuses offered to enemies in the Hades Paradox Cup. 4. New weapons and accessories, including a replica of Lexaeus' tomahawk for Donald, a copy of Vexen's shield for Goofy, and a crown for Sora.
5. A "theater mode" - menus where previously viewed cutscenes can be rewatched with English and Japanese voices by pressing L2 and R2. 6.
New cutscenes based from the Kingdom Hearts II novels were added: Some involving Roxas, including scenes of him conversing with Axel in Twilight Town while wearing the Organization's signature black robes. There are also additional scenes of Roxas and Riku, including shots of their second battle, where Riku takes on the form of Xehanort's Heartless, Namine leaving with Axel, and the Organization discussing their plans and commenting on incidents like Axel's death. 7.
A new secret ending video titled Birth By Sleep, featuring a number of new characters whose relation to the main series remains unexplained. 8. A new Drive Form called "Limit Form" has abilities From Kingdom Hearts 9.
Final and Anti Form have better chances of coming up in gameplay. 10. Secret features can be accessed in Final Mix by clearing Re:Chain of Memories first or Clearing "Final Mix" first then Re:Chain Of Memories.
Clearing Final Mix can also unlock secrets in Re:Chain of Memories it goes around. VERY IMPORTANT Better Compatibility and The Truth Imported copies of Kingdom Hearts: Final Mix and Kingdom Hearts II: Final Mix+ are region locked, meaning that they will only work in a Japanese Playstation 2. Both American and European gamers will find that neither game will load in their PS2. Many people choose to install a hardware mod chip in order to get around this region lock.
However, because of the disputed legality of mod chips, this is not recommended. (There is more to the list in a link bellow) --NOTE: There is a kingdom hearts hd remaster collection that will be released soon(hopefully),it was already confirmed to be released to the US so we'll get an english version of Kingdom Hearts(the first game): Final mix, fully remastered and for the ps3. The KH remaster titled "Kingdom hearts 1.5" will only contain the games before kingdom hearts II and the ds games will not be playable in the collection,they will only be a set of cutscenes in full remaster.
Also,we might get Kingdom Hearts II:Final mix for the us in an hd remaster for the us as well. Tetsuya Nomura said so himself"it be unusual for it not to happen". So we can except a Kingdom Hearts 2.5 hd remaster.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.