On a side note, I've noticed that probably the weakest point of this map is probably the actual battling component. As such, I'll be uploading a sides test map later tonight - open to everyone - to let them test out a little bit of my sides. Hopefully I can get some feedback that'll be able to improve this.
EDIT: Spira: Moonflow, the battle system tweaking map for Spira: Besaid, has been released. Please check it out (in the Released Maps/Mods section) and give feedback.
Update:
Here's a quick overview of "overdrives," since I just got this particular feature scripted out.
What is an overdrive? In Final Fantasy 10, overdrives were character-specific special moves that the character had access to after a certain amount of battling. In a similar fashion, these overdrives are available to you in Spira: Besaid. Each character can access one overdrive, but it may only be used once, and then after that you must kill a certain amount of fiends before the overdrive is available to you again.
What do overdrives look like? In Final Fantasy 10, these were elaborate animations detailing exceedingly good-looking attacks. Not so much here.

There's only so much I can do with particle editor, especially in light of the attack animations needing to be nearly-instant. So unfortunately, no attack cutscenes. However, I have made some special particle effects for each overdrive, so they retain some similarity to their Final Fantasy counterparts:
Tidus using his overdrive, Energy Rain:

Wakka unleashing Attack Reels against a hapless fiend:
How will overdrives work? As mentioned before, overdrives won't be available to you all the time. That means it would be wisest to save these powerful attacks for whenever you're in a battle with an extremely powerful fiend, or perhaps for when you find the odds stacked heavily against you. However, once you've slain enough fiends, a message will appear indicating that your overdrive has charged up. This message will continue to appear until you use your overdrive - it's best not to forget that you have this fantastic weapon at your disposal.
Additionally, overdrives are a by-the-character thing. That means, for example, if you've used Tidus's overdrive, but not Wakka's, you still have access to Wakka's. Likewise, if you charge up Tidus's overdrive, and you had just used Wakka's, you would need to charge up Wakka's separately to use Wakka's. Only kills made by a character count towards charging their overdrive. (E.g. if Tidus makes a couple kills, Wakka can't make a lot to finish charging Tidus's overdrive.)
Finally, you may notice I never mentioned Yuna - the third playable character in my demo map - in all of this. Why is this? Does she not have an overdrive? Well, yes - that is true. Yuna has no overdrive. This is because she has the exceptionally powerful ability to summon an Aeon - a powerful magic creature - to fight for her. In fact, there's a good chance that this Aeon has her own overdrive...
Edit: I forgot to mention this - to prevent the character from accidentally using their overdrive and missing, if you do accidentally manage to use your overdrive, and it doesn't hit anything, then all you need to do is return to a save sphere and reselect your character. You will have your one use of your overdrive returned to you.