Pretty Good, but a few problems.
I thought it was a fairly good mini-shooter, and it was fairly well-designed. I made it to the second part.
However, I realized that the gun and the actual mouse positions were a bit offset so that the barrel of the gun didn't match up to where the bullet went, which made it extremely hard to hit the very small targets that were the health and ammo pickups. Also, the hit detection was a bit shaky.
Overall, though, It was quite good. :)