BioWare played with our emotions quite a bit in the lead up to E3. The gaming world was left in limbo as the company teased us with rumors of Commander Shepard's death, only to finally let us know that your character started in the first Mass Effect will carry through as the main protagonist straight through the entire trilogy. Well, it will if you manage to keep Commander Shepard alive. This darker entry into the Mass Effect franchise will find Shepard making decisions that will ultimately build together into a web of your creation that can mean life or death by the end of the game. You'll only get to carry your Shepard on to Mass Effect 3 if you manage to survive Mass Effect 2.​

The E3 demo was lead by Mass Effect 2's Project Director, Casey Hudson. He opened by talking a bit about the background of this second chapter to the sci-fi RPG franchise. If you've completed the first Mass Effect, the sequel will recognize your save -- and all of the decisions you made -- and adjust the continuing adventure accordingly. If you let a character die in the first game, they're gone. If you made certain decisions that might alter the future of the human race in the galactic community, well prepare to bear witness to the consequences. Of course, if you haven't played the first Mass Effect game or lost your save somehow, you'll still be able to pick up Mass Effect 2 and start playing.​

The coolest change to the combat is that enemies now have individual hit boxes on all of their body parts. Shoot a robot in the arms or legs and you can watch them slowly tear to bits as they're ripped limb from limb. Shoot one in the head and watch the machine brains go flying. The same location sensitive damage also applies to human and other living beings. Head shots here we come.​

Of course, we all know what made Mass Effect's combat so fun was the ways you could mix and match the different weapons and skills. That same formula is returning in an expanded form. Nine new classes of weapons are being added including those of the heavy nature. We saw a missile launcher combined with a force pull power. The result was an enemy being pulled out of cover and then being blasted off of the raised walkway by the concussive blast emanating from the missile that hit nearby.​

But the really interesting stuff was in the concept of major character deaths. Depending on your choices, any main character can permanently die in Mass Effect 2, which will lead to some fairly stunning plot twists.

To illustrate this point, BioWare skipped ahead to a later section of the game. An unknown alien force had torn apart the flagship starship Normandy, the ship near collapse. Shepard issued an evacuation order, forcing Linara to head to the escape pods. Surrounded by chaos, Shepard slowly made his way through the fire to a doorway--and then the booming sound dropped out entirely, sucked away by the vacuum in Dead Space-style, leaving only the rasp of Shepard's desperate breathing.

Walking on the skin of the dying ship, Shepard eventually found shipmate Joker, who was attempting to save the craft. But following that moment, the enemy ship fired a massive beam weapon at the Normandy, violently splitting it down the seam. Shepard was knocked about in the fury, then was entirely jettisoned into space. The hero flailed about in space as his air leaked out from the wrecked spacesuit, then disappeared into the black.​

During the guard's interrogation--"Tell me where the bomb assassin is!"--players will eventually see a flashing exclamation mark in the lower left corner marked with the left-trigger icon. Upon pressing it, Shepard simply pushed the guard out the window, leading one character to quip, "So when do we read him his rights?"​