What I loved about the demo is I thought I broke the game a couple times with the skills, only to have the next boss wreck me for my foolishness. For example I initially got everyone to have multitasking and either two handed or ninja to attack like 6 times in a row each using my brave points. I destroyed the first dungeon and one rounded the boss.
The forest dungeon made it a little tougher with the plants that responded to attacks by spawning another. I added the adrenaline skill and it was back to just blowing them up to a million attacks. I fought the turtle and my strategy was completely nullified by his defense, so I had to go back to the drawing board... Time for 4 black mages. Their ability is to amp magic the more of them you have, so I easily one shotted the turtle with blizzaras. This worked on the next boss too, but then the dragon wrecked me just like the turtle originally did.
My last broken strategy was the ninja move that dodged attacks, with the skills that gave you 1bp after Dodge and buffed your stats after dodge from red mage and sword master I think. I was able to take virtually no damage from the last two bosses this way. I am sure later bosses will punish me for that set up though and I can't wait to make new strats.
Of course I could have probably just played normal white mage plus x parties but it's way more fun to see what you can get out of the brave system. With autobattle and the speed up button/encounter rate config grinding new skills to try is completely painless. day one purchase.