Classic Newgrounds material...

Awesome!

This is AWESOME! Good work!

Sorry, but Newgrounds requires window.event handling javascript so that the page does not scroll when you press keys like the down or up keys or the spacebar. Therefore your game is unusable. Also please change the music. You may want to use Aseprite to make your graphics.

I'm sure you put a lot of effort into this, but you can do better. keep making games!

Add the following code inside your index.html in a script tag

var keys = {};
window.addEventListener("keydown",
function(e){
keys[e.keyCode] = true;
switch(e.keyCode){
case 37: case 39: case 38: case 40: // Arrow keys
case 32: e.preventDefault(); break; // Space
default: break; // do not block other keys
}
},
false);
window.addEventListener('keyup',
function(e){
keys[e.keyCode] = false;
},
false);

Holy shxt! Don't you think I've tried this before I typed a single letter in my comment?
I only bothered to point out this problem and give you the solution because I went through the very same thing when I published my own game here. Next time I won't even bother.

Interesting and challenging game. Work needed on the sprites though. Keep going!