For more details about how to make the game, screenshots and downloads of three game versions, see my website. It is released under the Creative Commons license, which means you are free to use and modify but please acknowledge the source. Feedback is appreciated.
Here are some advanced features incorporated into version 3:
- Create a controlled relentless advance of enemies (serried ranks or phalanx)
- Use a variable to control the speed of the enemies so that the enemy can increase speed progressively as the game progresses
- Lives for the character (shooter), which are displayed on screen
- Power up object provides increased powers, destroy more enemies with one shot
I wrote about some of the design issues and problems in another recent blog, representation of design decisions