You can't equate a 5 star rating scale to numbers...so 3 stars is not 60%.
I never really got why people always thought 60% was bad anyways, except they made game grades to be like school grades, so anything less than 60 is failing...but that's another story for another day
3-Stars is a middle of the road type of game, it's neither great nor is it bad. Never known why the 5 star concept was THAT hard to grasp.