How many downloads did you have before that happened? Also, do you ever have people adding the game to their collections? But no additional ratings or comments?
People very rarely comment (ratings are more common), but they often add games to collections. And I don't remember numbers, but the old rule of thumb from publishing (and commerce in general) applies: maybe one in ten people will check out your game. Maybe one in a hundred will get it. Maybe one in a thousand will offer any feedback. Don't get your hopes too high no matter your price policy.