Pretty well done, and yes, I was also startled when Jason first pops up. My compliments to those involved. Great music too. Sets the mood quite well. And to those who have trouble with the NES battle, you have to dodge!
For some reason, the very first powerup to initiate won't disappear. It functions correctly, but won't disappear. Subsequent powerups all work perfectly. I also can't get the mini bosses to work properly.