Some tips from me. You can't win the game with just one type of weapon. My favorite is Hearth Piercer. And for money, Achievement give you a lot of money, just take a peek of it. Later I'll tweak some weapon and the spider. For hitbox, we've try and make the game so the hitbox is at the same size and shape of the hero. If it is because of the bat projectiles, it give a splash damage.
We've upload a new version of the game. For my personal impresion it is way easier. At first we just want to make something challenging. But from reading all of your comments, we've decided to make it easier. Hope we can make it better and better for you guys.
We're uploading a new version now. Fix some ai bug, 1st level is easier now (I'm sorry for the one that have through the hardcore version :p) and add the arrow key feature. Hope you guys still want to help us improving the game.