tips: the reason u start a part with no energy is cuz u don't have enough agility (blue boots stat thingy). Raise it and u'll get more energy to start with.
Also a complaint/suggestion: when u open a box, isn't it normally the case u're supposed to get an item with an X on it on the items list, the ones that you can't get on the field? so annoying
One issue.... why the heck do u get exp proportional to the number of units defeated? The last two trials have literally one unit as the enemy and therefore gives less exp than the first battle of the game. wtf?