You have some performance issues. Consider adding a method that deletes the lasers once they leave the screen area. As it is, the longer you play, the slower it becomes. Also, an alternative choice is to draw a line using a greenfoot image. This way, you would check for anything in the line. It would look much more 'Death-Laser' -ish, plus it would run like a breeze.
2015/7/2
2015/7/5