It's a good game, well made with interesting environments, some pretty hard gameplay and some fun elements. The plot could have been better, but that's not really any problem for a flash game. It was enjoyable and the enemies were varied, even those damn bats.
But... it's ridiculous in its difficulty. You gave us no warning that saving inside the dungeon was pointless, so I wandered for half an hour, reached the boss, got spanked, and that was that. Half an hour wasted. I'm not playing through that again.
Consider resetting to the start of the level on death rather than the frankly absurd resetting of half the game, and also remember that as there is backtracking involved, try not to swamp the end points with enemies - a lot of the time, I re-entered the room to find myself covered in bats and those rock monsters, with damn little all I could do about it but watch as they removed all my hearts. Perhaps turn off the respawn, or create more safe areas around the doors.
I'd also like to see more weapon versatility, like some form of throwing weapon? But it was well made, just a little too infuriating to play through.