This time I have created a karate game who will take you through an unlimited number of levels, with enemies that get stronger and smarter as you advance. It's all in here, starting with a karate-style camera that tracks the players, zooming in and out as they come closer or move away from each other, and going on with four different types of kicks ("Z", "X", "C", "V"), a key that blocks the attacks to the head (space), etc.
Move the player using the left / right arrow keys and may the force be with you! (feel free to replace this with something more karateish).
I didn't think that you were going to scroll all the way down here, but since you chose to do that, I'll tell you a secret: all the code is very well commented, as always.