Version 3.1 was created to allow Heroes to become even more like animals than 3.0 allowed. The first Heroes to try it out were the members of Angel Squad. The upgrade was a sucess, and more Heroes have since been upgraded to 3.1. Version 3.1 was instrumental in bringing down the criminal organization V.I.R.U.S.
Version 3.1 is similar to 3.0 because it is based off of animals. But the similarities end there. This is a quick description of the workings of Version 3.1. Heroes upgraded to 3.0 get animal powers. 3.1 gives the Hero animal DNA. Each 3.1 Hero recieves a certain amount of animal DNA, making them part animal. For example, Natalie Breez was injected with lizard DNA, resulting in a part Hero/part lizard hybrid.
Version 3.1.1 was a minor edit, a simple program entered into the Heroes. The program allows the 3.1.1 Heros to be more fierce and aggressive. However, the program had some unexpected side-effects, and was remodeled into version 3.1.2. 3.1.2 had no side effects, and was programed into all 3.1 Heroes.
So far there have been no further updates past 3.1.2.