JS Space Invaders

rewrite this project with completely new with javascript code. https://jsfiddle.net/bmojica1/hj5pfvny/ If you could do it in half the amount of code, that would be preferred.
It should include at least 4 of the following:
– DOM element creation, deletion or modification
-DOM traversal o Capturing and handling events (beyond just a “Do it!” button
-Creating and handling a data structure (JSON, custom objects, etc)
-Form validation
-Closures
-AJAX
The code for this project should have clear comments explaining the steps and techniques being used in the project. The graphics and gameplay aren’t required to be changed, but can be. The deliverable should be sent via a text document I can cut and paste into jsfiddle.net.