I figured I'd have a go at explaining the system to people that don't understand. Thanks to everyone that theorised with me and Blank, and lots of credit to you for working out what the bar on the right does. XD
The system is a turnbased/realtime hybrid, similar to FF4 - 9, but with some more dynamic elements.
-The ATB fills up in real time, similar to the systems in FF4 - 9.
-You can input commands as soon as an Action (one section of the ATB) is full, meaning you don't have to wait for your ATB to completely fill up. You could use a command when your ATB is only a third of the way full.
-Your character doesn't use commands as soon as you select them. Instead, you store them in the Input Slots and then press triangle (Execute) to use them all at once.
-Using more than one command at a time will create a combo. Every combo has a unique animation, meaning "Attack-Attack-Fire" will look different to "Attack-Fire-Attack".
-Your ATB will not fill up when you are Executing commands.
-You choose your target enemy
before you select your commands.
That's what we know for sure. If you have any questions, feel free to ask.
These are just theories, so don't take them as facts-
-There is a dodge move, completely seperate from the commands.
-Whether or not there'll be free movement is not known, it could go either way.
-You will have a leader during battles (represented by the yellow flag).
-There may be some kind of AI system to control allies.
-Getting hit by an enemies attack may cause your combo to end prematurely.
-The Cure command is grey. It would be a serious balance issue if you could use Cure whenever an Action was filled. Maybe the command is on a timer, so it can only be used sparingly?
-The bar up the top right (I'll call it the Break Bar) seems to have something to do with the enemies defence/guard. Every time you hit an enemy, the chain number goes up, the Bonus percentage will increase, and the yellow bar will fill. The yellow bar is constantly emptying, I'm guessing if it empties completely the chain/percentage will reset.
When the yellow bar is filled, the chain number turns to "Break" (there is a visual cue for this as well, two circles fly out from the enemy). The yellow bar then empties continuously, regardless of how many times you hit the enemy (meaning you have a limited amount of time to use Break).
(Note the circles)
Every time the character uses Launch, the enemy had been "broken". I believe when you Break an enemy it becomes possible to use certain techniques (like Launch). Therefore, if an enemy isn't broken, you can't use Launch (that seems like a fair balancing feature).
Certain actions seem to cause the bar the Break instantly. For example, every time a PSIcom was hit by Fire, their bar would Break. The giant mechanical boss was also instantly broken by Fire, while the four legged creature later on was broken by Blizzard (cast by one of the side characters, not Snow).
I've also noticed that every time a bar Breaks the character has just completed a full combo of three attacks. Unfortunately there isn't enough footage to tell if this is how to Break an enemy or if they really do have elemental weaknesses. =(
I believe every enemy has a seperate Break bar. When Lightning kills one of the creatures on the ice, the Break bar up the top right completely changed (locking onto another enemy?).
I think the Bonus percentage has to do with how much the Break Bar fills up, not how much damage you're dealing.