I did a little investigating and it turns out that 5 days ago, the "College Lacrosse | The Video Game" Facebook page (which has about 175,000 fans) requested help from its fans to raise the ratings of their games. Now, there's nothing wrong with asking your fans to rate your game positively, but it looks like some of their fans were overzealous and started 1-starring other high rated games in attempt to make it easier for the Lacrosse games to rise through the ranks. Now for something like Z0MB1Es which has over 50,000 ratings, a sudden influx of 1-star ratings isn't going to do much, but since our game has been out for less than 3 months and only had around 1500 ratings, it affected us big time and we dropped 5 ranks. It affected our earlier game a bit as well - whereas before it was going back and forth between the #4-5 slots, now it's #6. In contrast, the Lacrosse games which were in the middle of top 20 best rated (I don't remember the exact positions) are now ranked #4 & #5.
Now I have no idea how this sort of thing could be prevented, but I'm really upset. We were really hoping that our upcoming patch would give our game the little push it needed to finally stabilize in the top 5 rated. Now, it looks like we'll be lucky just to get our old rank back.