You just saw everything that there is to be seen in the Vatican. Why not topping of your experience with a climb to a breathtaking view? True its 500 stairs and not everyone is able to do it but you can pay 2 more euros to the 8 euro ticket to use the elevator and skip 200 stairs.Believe me , it is worth it.
PS. Even though 500 steps sounds scary , the first steps are not that steep , making the climb more like walking uphill rather than climbing stairs.