Thanks for playing! I think the bug you found with the axe is actually intentional. The “walls” in that level are actual hills that you can push yourself down with a knockback weapon. This effect is not necessary for completion of that level, which is why it may seem like a bug, but it is used in the bear levels and in the final level, which features a weapon that applies knockback without dealing damage as you suggested. I definitely agree that this idea should be explored more.