it's not overly difficult. You can complete the entire game at low levels with the right strategies and augments. Or the opposite, you can complete the entire game by over leveling. It's really only the optional bosses on the New Game++ that you have to have the optimal setups. Even then, there are different ones you can choose to use.

Basically, just pay attention to enemy weaknesses and what's going on during the battles, and you'll be fine. And heal almost every turn if not every turn later on.

THE JACKEL