The Bronze Spear is required to complete the dungeon; several points in the dungeon there are switches across a pit that must be struck by a spear, but the Horn Spear isn't heavy enough to trigger them. The Bronze Spear is able to hit these switches, even if the player has not levelled it up enough to throw it. The Bronze Spear continues to be a useful weapon through Antiqua and into Gothica, as many flying enemies like the Bone Buzzard and Dragoyle are easier to pin down with spear throws than other weapons.
The Bronze Spear's level 2 attack is to throw it forward slowly, striking the first enemy it hits. The spear will lose altitude when thrown horizontally. Its level 3 attack has the Hero wind up before throwing it, resulting in a longer lag before releasing the attack, but a faster-moving projectile with higher power and the ability to strike multiple targets.