The concept itself is fine and can be extended in many different interesting ways. And should be, since right now it's way too easy to win by just flooding hero with as much traps and monsters as you can. There isn't much room for the strategy: you create a snake-like path and put as much enemies as you can. Or am I missing something?
Anyways, I enjoyed playing your game and it was much more satisfying to be an evil dungeon lord killing the hero than i would be the other way around ]:->