Blue does not seem to take any damage. Other than that, I believe it is working as you want. One of your players, the blue one preferably, should probably start on the right side of the window.

I created something similar using my QActor superclass for quality moving and rotating. It allows for fractional speeds and rotations. I also had the stars speed up as they moved away from the center, giving the viewer the illusion of moving forward through space. It would be a good demo for my QActor class.

After you create a new attack object (in the four blocks in you Map class that check for the 'q', 'e', 'u' and 'o' keys), add a line similar to this: at1.map = this; or at2.map = this; Currently, only the 'o' key will decrease healthpoints as you only check for damage in the 'o' key detection block.

Couple things of note. The first one is that you are creating more and more stars without ever removing any from the world. You may notice that the speed of the scenario slows down the longer you run it. Eventually you will throw an exception if run long enough. The other thing is that if you watch the behavior, you will notice that the once along the 90 degrees lines are the slowest ones; the ones at 45 degrees are a bit faster; and the others are even faster. This coorelation is due to the speeds that they are going. Also, the slower ones will, by design, be closer to each other than the faster ones; so, the 'line' they form is more prominent for that reason also.