Only the ratings that are given count, missing ratings do not count against a game - but they do mean that the ratings that it does receive count more. For example, if a game only has a single “Fun” rating of 5 stars, then it will end up with a 5 star rating. This means that it’s a good idea to rate as many games as you can so that every game has a good accumulation of ratings to average together.
I’ll probably leave the ratings open for a couple days to make sure everyone has a chance to rate. Once I see the ratings stop getting updated, I’ll close them out and announce a winner.