Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
If you are a fan of any or all of the previous Borderlands games, as I am, then you will love this game. And even if you aren't it's a great looter shooter. There's not much of a story, but it's not really needed. If you like to kill things and collect lots of different loot, this game has both in abundance. There is also a bit of RPG and MMO elements in there too. Bottom line is that it is a whole bunch of fun and I highly recommend it.