The Decompression Windows are a new feature in Dead Space 2. They are large windows that you could shoot in order to cause a vacuum that would suck anything in the area out into space including Isaac. Shooting one would trigger a sequence where all Necromorphs in the area are sucked out into space and Isaac slid across the floor toward the window. The player had to shoot a red switch at the top of the window in order to close it. If Isaac did not shoot the switch, it was an instantaneous death.
- It was recommended that you should stay far away from the windows if you planned to shoot it as you would not get enough time to shoot the switch if you stand too close.
- Decompression Windows had a limited range. This could be easily seen in Chapter 7. There was one room that had a Decompression Window. If you stand far enough to the side when you shot it, you would remain unaffected while everything else was sucked out.
- Also, the windows only affected the room that it was in. In Chapter 4, the only Decompression Window was opposite the door to the hall. If you stood in the hall, but close enough to the room to keep the door open and you shot the window out, the room would decompress, but you would not move. The window would close after some time and you did not have to shoot it to close it. However, if you entered the room while it was decompressing, the sequence would initiate and you could still get killed.
- There are two Achievement/Trophies involving Decompression Windows. "Skewered in Space" required you to impale a Necromorph to a Decompression Window, causing it to break. The other one, "Vacuum Cleaner" required you to kill twenty Necromorphs using Decompression Windows without getting sucked out yourself.
- A strange thing occurred after Isaac's battle with The Tormenter. When he crashed through the window, all of the oxygen was sucked out, but none of the candles on the floor are affected and none of the lights are extinguished.
- It was extremely strange how the Window's emergency shield rose only when Isaac was in position to be killed by it. If this was a feature to prevent multiple people being decompressed, it did not explain why the shield did not rise after a Necromorph passed through.
Should Isaac fail to close the window in time, one of the following death scenes would occur:
- Isaac attempted to get away, but the window's emergency shield rose, pinning him to the ceiling. It continued pressing against Isaac's torso until he was split in half.
- Same as above, except the shield was pressing against Isaac's back until he was split in half.
- Isaac managed to stand up right next to the window. However, the shield rose, catching both of his arms in between the shield and the ceiling. His arms are severed and Isaac fell to the ground. He died from his injuries.
- Isaac got pinned by the shield at his torso, but the force of the vacuum still sucked him out. As he continued to slide through, his arm got caught. It got severed and Isaac flew out into space while his arm fell onto the floor.
- When you had to close your first Decompression Window in the beginning of the game, should you fail to do that, Isaac was sucked toward it, but cringed to a table. The force of the vacuum was enough to sever Isaac from his arm. He flew toward the window and bashed his head against the wall before getting sucked out into space.
- There was an unused death scene in which Isaac attempted to get away from the door while on his back, but both of his legs got caught in the door. Isaac attempted to pull them out, only for them to get severed, leaving him to attempt to crawl away and bleed out shortly after. This was seen in the Dead Space Gameplay Reel video currently up on YouTube at the 0:23 mark.