One of the reason for the low number of 5 stars is that noone here has platted some of the hard games out there and as a result they don't have a rating as Arcturus only rates games that someone on this forum has platted.( Star Ocean the Last Hope, Battlefield Bad Company, Warhawk, Lost Planet 2 all would be 5 stars if someone had the plat here).
Whereas if a game is easy you can bet someone on this forum will have platted it, just for the points...