The Decompression Windows are a new feature in Dead Space 2. They are large windows that you can shoot in order to cause a vacuum that will suck anything in the area out into space, including Isaac. Shooting one will trigger a sequence where all Necromorphs in the area are sucked out into space, and Isaac slides across the floor, towards the window. The player has to shoot a red switch at the top of the window in order to close it. If Isaac doesn't shoot said switch, it's an instantaneous death.
- Is recommended that you stay far away from the windows if you plan to shoot it, as you will not get enough time to shoot the switch if you stand too close.
- Decompression Windows have a limited range. This can be easily seen in Chapter 7. There is one room that has a Decompression Window. If you stand far enough to the side when you shoot it, you will remain unaffected while everything else is sucked out.
- Also, the windows only affect the room it's in; in Chapter 4, the only decompression window is opposite the door to the hall. If you stand in the hall, but close enough to the room as to keep the door open, and you shoot the window out, the room will decompress, but you, in the hall, will not move. The window will close after some time and you do not have to shoot it to close it. However, if you enter the room while it is decompressing, the sequence will initiate and you can still get killed.
- There are two Achievement/Trophies involving Decompression Windows. "Skewered in Space" requires you to impale a Necromorph to a Decompression Window, causing it to break. The other one, "Vacuum Cleaner", requires you to kill twenty Necromorphs using Decompression Windows without getting sucked out yourself.
- A strange thing occurs after Isaac's battle with The Tormenter. When he crashes through the window, all the oxygen is sucked out, but none of the candles on the floor are affected, and none of the lights are extinguished.
Should Isaac fail to close the window in time, one of the following death scenes will occur:
- Isaac will attempt to get away, but the window's emergency shield will rise, pinning him to the ceiling. It will continue pressing against Isaac's torso until he is split in half.
- Same as above, except the shield will be pressing against Isaac's back until he's split in half.
- Isaac manages to stand up right next to the window. However, the shield rises, catching both of his arms in between the shield and the ceiling. His arms are severed, and Isaac falls to the ground. He dies of blood loss.
- Isaac gets pinned by the shield at his torso, but the force of the vacuum still sucks him out. As he continues to slide through, his arm gets caught. It gets severed, and Isaac flies out into space while his arms falls on the floor.
- When you have to close your first Decompression Window in the beginning of the game, should you fail to do that, Isaac will be sucked towards it, but clings to a table. The force of the vacuum is enough to sever Isaac from his arm. He flies towards the window, and bashes his head against the wall before getting sucked out into space.