Someone on this board, I can't remember who, said the game would be good if it came with a better instruction manual.
Probably me. If you have any questions about how to play it I'll be glad to answer them ~~~ Just PM me or something.
I found Unlimited Saga pretty intuitive, actually. The only odd thing I found is that you use the d-pad to control the menu and the stick to control the characters, while on the map screen. Also the thing where you can cycle between different objects at your current location when you're in the... interaction menu. I wasn't immediately aware that you could do that.
The manual DOES neglect to mention a couple things like how speed affects combos and how different weapons do pierce v. strike damage and why that matters. In the former case, though, it's almost identical to CTB in FFX, and in the latter case, you can basically tell by attack animations (beams/straight lines/stuff like that = pierce. If the attack effect looks more like an explosion, it's strike. I think there's also blunt but it works pretty much the same was as strike. And basically, pierce focuses more on LP damage and strike focuses more on HP damage).
Anyway a few general tips.
1. Weapons have limited uses but I'm pretty sure that if you run out of uses mid battle, you can keep using it for the remainder of that battle.
2. The equipment system is more or less identical to FFXs. Weapons and armor aren't so much inherently unique but they have different abilities. Generally, since LP is more important than HP, you want armor with skills like Life Protection and Pierce Protection/O Pierce/whatever it's called (since pierce does more LP damage than strike. Or slash. Or whatever).
3. The order you issue commands in battle is actually how your dudes are placed on the field. There's either two or three rows depending on a couple of things, primarily how many dudes you gave orders. If you give commands to four different dudes, you'll only get two rows, basically. AFAIK this MOSTLY affects odds of getting attacks, so you want to give commands to guys with better armor/more LP/more HP first. As far as the actual order that commands get executed in, you press left or right on... I think the d-pad, maybe it's the stick, in battle to select who you want to go first. That'll make more sense if you actually look at it in the game.
4. Basically, you want some people to focus on slash attacks and some to focus on pierce attacks. The way HP and LP work is that HP is sort of like "armor" and LP is your REAL HP. The higher your HP is, the less likely you are to lose LP, although certain attacks can still do LP damage directly (which is why you want armor with Life Protection and Pierce Guard/O Pierce!). Same applies to the enemies. So you send out the slash attack guys first, have them do a lot of HP damage to weaken the enemy's defense, and then you send out the pierce guys to rack up massive LP damage. Doesn't matter so much for regular enemy encounters, but it's really helpful with bosses.
5. Play as Laura or the uh older magician chick first. They're easier. Kurt isn't particularly hard but he and Ventus both have this one quest called "Veil of Sorrows" or something which is sort of a pain because your party gets split up to do it and the map is really confusing.
6. It has a lot of RPG trappings, but it's by far more of a turn-based strategy game than it is a straight-up RPG.
Anyway, unintuitive is something like Powermonger where you have a million little buttons with pictographs on them and no tool tips. http://www.mobygames.com/images/shots/original/1226967068-03.png
Seriously I have no idea what any of those do.