Yeah balancing was really difficult. Enemy health and evasion scales with the world level, but they do have a cap. Player hit chance bonus also scales with your level and eventually it should be enough to counteract the boss's maximum evasion amount.
I spent about a day or so doing balance tweaks, but the weapons either felt too weak or too overpowered early on. In hindsight I probably should have got some people to playtest, but I was just exhausted.