I'm at Rank 6-1 and everything else becomes hard for me.
Why? I actually think there's so much still lacking.
It's like the game doesn't want the players to finish the level. In fact, the monsters and traps deal more damage when you go deeper.
The thing is this game needs many changes like:
-Aside from being granted more health percentage, the armors and helms should grant health regeneration.
-The traps must not increase in damage as you go deeper in game and it should also affect monsters as well (because it's so unfair!!!)