I think the cover photo and name does affect it to some degree (I think you have a good name; it's nice and to the point). The best thing you can do is to post here (like you did!) and rate and comment on other people's games.
As for how many ratings you should be expecting, I don't think that's really the point (not a good metric to judge a game by) but... the median yesterday was 8 according to someone and the mean is currently 15. Keep in mind that there are a few games pulling that way up (there are a few with over 100 rates) and there are other games that still only have 1 rating.