I had the chance to test Injustice's gameplay in Milan, this wednesday.
The first thing that comes to the eye is the beautiful graphics this game has.
The polygonal models of the characters and some secondary elements of the stages are astonishing! There's a good use of anti-aliasing technologies, the animations are smooth and fluid and the game plays faster than MK9. However, sometimes you can see that some frame has been cutted to make the animation a bit quicker.

Gameplay wise, I have to admit it's "less" awesome than MK9, but awesome nonetheless. The juggles are harder to execute, and you can reach 8-9 hits combos simply by using two buttons.
My first trial was with Nightwing. His kali sticks are excellent in close range and by mixing up all the basic moves with the "square" and "traingle" buttons you can easily achieve 8-9 hits combos. His "Bo" fighting style is more oriented towards long and medium distance combat, as he is less quick, although more damage oriented. Unfortunately, his Bo stance didn't fit with any of the special moves he has, except for his "Back, forward+ cross", which works more or less like Cage's Shadow Kick from MK9 and it's a easy way to end a combo with your opponent in mid air.
Nightwing has a special move where he electrocutes the ground using his sticks, it was "down, back+triangle" but it's easy to avoid and almost un-juggleable.

A firend of mine, attending the event alongside me, tried Batman. He is well balanced between gadgets and martial arts. he is quick and strong, although he lacks any good move in the close combat department.

Later I had a shot with Superman and I Got a easy win against the worst character of the bunch, Solomon Grundy.
Superman is quick as hell, powerful enough to deplete his opponent health bar very quickly, and plus he has a special power that doubles the damage inflicted. In other words, I depleted the second health bar (the red one) with 5-6 hits in total. His special move it's the easiest to connect; unlike Nightwing, which has a limited activation area (like Jax's and Kano's x-rays), Suppy covers the screen totally.

Solomon Grundy really sucks. He kinda reminds me of Zangief from Street Fighter. His throws are not that good, he is slow and doesn't deliver that damage either.

After all this, I tried the 1 vs CPU option. The AI is terrible, but NRS has still to work on this. The loading screen between fights kinda reminds me of the tower from MK, although it is developed differently.
Rather than a vertical route, it follows an horizontal one. There is a small render of your character's shoulders, and one on one all the versus screens of you enemies. If i recall correctly, these versus screens are different from the ones used at the select screen.


There are a lot of things to improve: get-up and defeat animations between fights and "health bars", the stage interaction is totally dependant on the "L1" (or left trigger), so just reach one of the extreme sides of the stage to activate a stage transition (also during a combo, also in mid-air) or interact with the stages.


Another good feature is the new "throw" system. It works exactly as the one presented in MK9, although the throws are more spectacular and with more dramatic camera angles. For istance, Nightwing jumps unto his opponent's torso (Like Mileena), kicks him to the face, jumps back and then gets up using a spectacular kip up.