At first, I thought the hitbox in front of the player was too large, but then I noticed the asteroid images are apparently being resized, so I suspect the hitbox for the asteroids is assuming the original dimensions, causing collisions in apparently open space. I'm only assuming this is what's happening, since I don't want to wade through that much javascript to find out.

Since this seems to be a demo i'm not going to get too pedantic about the gameplay, but that definitely is something you would want to address in an actual game.

thanks, the meteor is replaced with an explosion, but doesn't keep up with the scale

you're right, it's a technology demo I had fun making, not that much invested in game-play

thanks for the pointers

Cut to Sam Jackson going "ASTEROIDS... HAVE YOU EVER SEEN IT?"

(This is a side scrolling game which has rocks to shoot)

The licensing notes all over the source code are pretty obnoxious. I mean 27 times in one file? Come on!

haha, you mean the polymer licensing right? I have none :) actually you can even see the full code here, it's open sourced https://github.com/catalint/asteroids

also, it's 27 times because of bundling, and their way of typing license in each file header

Try it on mobile also