Well, this game is certainly very nice, I finished it, with the hero sword and all. Very entertaining!
However, if I may, here is what I think could be improved:
-Difficulty. I think it took me only 4 restarts to make it through all the levels with careful upgrading and skill distribution. Make it much, much harder, or at least, give the player a choice.
-Monster and chests grind fest. Would be nice to have quests (I know one in the tavern about blue berry) but the game mechanic doesn't really allow this very much since you lose everything on going back to town.
-Diversity in level design. Like for example, you need to go to the other part of the map to pull a lever to open the exit door. Would require you to actually clear more of the level, I dunno. Or have one enemy on the level drop a key required to go to the next level.
Having sometimes hand-design rooms (not just the secret part) would add a bit of diversity to this randomly generated (?) levels. I understand it's a cave, but it's a strange cave, it allows you to do anything.
-Item menu is confusing on how it work with clicking an item showing its stats, and clicking another item kinda switch both item instead of showing the second item stats... anyway, maybe it's a natural for you, I just find it odd and confusing with what I'm used to in other games.
-Stats description. I'm not a huge rpg fan, so maybe I don't understand every stats on how the affect the combats. So the resistances for example, 1 point in defense = 1 point dmg reduction I guess? and each elemental resistance is specific to the element? So one point in defense is much more desirable than a specific elemental resistance, right, since it reduce damage regardless of the damage type? I just have no way to know this.
Good job, dude, keep up the good stuff, it's rare to see a game with such long playtime that are enjoyably in newgrounds! Thank you!!