java script ASTEROIDS classic

I make Asteroids using pure JavaScript. by using canvas API    I structured everything so you will completely understand every line of code. Play it and then give me your recommendation 

If you want to make games you have to know how to make Asteroids! It requires you to understand moving in a 3D space, collision detection, inertia, velocity, rotating shapes using math instead of rotating the canvas, reacting immediately to user input, animating polygons, creating and destroying objects, trigonometry, and numerous other related topics!

If you learn how to make Asteroids, Pac-Man, Mario and Zelda you can make any 2D game. If this tutorial gets views I will make all of the above using pure JavaScript. 

 As you probably noticed this game just for learning how to develop games with pure JavaScript to uplevel my skills in this language please leave me your thoughts/recommendation in  the comment...