Ed Boon of NeatherRealm, the creator of "Injustice," confirmed on Twitter that the first set of codes was released last January 27, Fans and players can now sign up to get an access to the game Injustice 2 Beta by signing up on their website, where they can go grab the codes that they can use to access the game. The Beta testing is available on Ps4 and Xbox One.
Some of the characters that the players can use are of course Batman, Superman, Deadshot, Harley Quinn, Wonderwoman, Super Girl, Aquaman, Atrocitus, Gorilla Grodd and Blue Beetle.
The Injustice 2 gameplay is somewhat like the same as its first game Injustice: Gods Among Us, character traits, environment interactions, clashes and stage transitions. Furthermore, super meters can be used to execute special moves and also it unlock super moves when fully charged and players can now do an "evasive roll" that can be used to execute combos early in the game.
Something new has been added to Injustice 2. It is called the looting dropping system or "gear up system" wherein players can equip character costume pieces and equipment that has special effects that can be used in the fights. The creator of the game Netherealm Studios stated that the "Gear Up" system somewhat has mechanics like the ones used in Role Playing Games (RPG's) to give players more equipment during the match that will suit their play style. Also, the "Gear Up" system allow the players to customize the look of their characters and enhance their abilities more likely adjusting the character's speed, strength health etc. The characters have five gear slots to equip their different costume pieces and they also have two ability slots to equip different special moves and a shader to change the color of their gear.
Here is the link wherein players can sign up for free Beta Codes.