Step One: Watch Mary Rose Cook Live Codes Space Invaders from Front-Trends. (The second worst conference name ever?)
Step Two: Fork this gist.
Step Three: Respond to this question in your fork: What is one approach you can take from this Mary's code and implement in your project?
Step Four: Totally Optional: take a look at some of the other forks and comment if the spirit moves you.
Liked how she writes the code that she wants to happen in the game, and then build the variables, functions & methods to make that line of code work. Aka invadersBelow