No, it was made harder. WD didn't like the fact you could use the weapons for free, and modified the game so they consume the spirit gauge as ammo. And some of the best weapons EAT the gauge darn quickly (e.g., the dragon beam).
In the Japanese version, the spirit merely controls the weapon's strength, and is decreased when you are hit by attacks from the same color as your current one.
They also made all weapons a LOT more expensive, forcing you to keep arsing around the levels, beating dead horses for money, something you weren't required to in the original version, where you eventually get enough money to buy upgrades.