I think this shows potential! It'd be handy if the player could get some sort of visual or audio cue as to when they are getting hit, and when they are hitting the boss. As well, I think it'd be handy to have a health bar for the player, so it's not quite such a mystery as to how much health they have left. It feels a bit empty without any audio... any sound effects or music would be nice, they even don't have to be your own. In any case, I think with a bit of tweaking, this could be a pretty fun top-down shooter!