There are a lot of missing sound effects example:
There are no character ability sound effects. (When you equip a character there are no sound effects).
There are no battlefield songs or the drums sounds. (When you go into the battlefield there is no background song for the battlefield and drums sounds).
There are no equipment sound effects. (When you equip an equipment there are no sound effects for the equipment).
When your summoning character or item does not have sounds effects. (When you click summon sure there is a sound but the rest doesn't have any).
There are no mercenary sound effects. (When you equip the mercenary there is no sounds for the mercenary being equip).
The bug is small. Again I will still recommend it, the gameplay itself is very well done. From the character, enemy and bosses design are also very well done. Mainly the game stands out is at the party set and the cutest of the characters in the game{note: this is only my opinions}. The party set up is very customber. Not all game give you a lot of choices to custom your party.
If I find anything I need to add I will add, so sometimes I will edit this.