Thanks for the feedback! I just pushed an update to make the arrow piercing upgrade gradual (pierce through 1, 2, 3 enemies) which should help a bit but the bow is still too powerful, I'll work on the balance more.
Adding the weapon abilities is a great idea, I'll definitely explore that, thanks for the suggestion!
I'm also planning to add more weapon-specific upgrades, maybe a special stick attack that blinds the enemy, 360 degree mace swing etc. If you have any other suggestions, feel free to shoot!