I forget if you were making this game mainly for phones or if that wasn't the case. I feel like the arrow key controls are sort of finicky in regards to how quickly they make you turn but other times not at all - I figure there's something to do with the gravity pull of the spheres but since going full thrust ignores it I haven't gotten used to it yet. I wonder if phone controls, if that is a thing, would change that somehow.
Other than that, the game looks good, albeit blurry if you don't maximize the web player (guess it's rendering at 1080p regardless). The sound is pretty quiet, but turns super loud during the scoring screen, specially so for the sound that plays once it's done counting score.
I was a bit confused by the sword-icon powerup firing lasers. Also, if you have a shield and it breaks, it makes it really hard to see your ship (and which way it's facing) for a second. Lost a run to that.