Insert an Xbox 360 controller. Pause game play, then enter one of the following codes. A sound will confirm correct code entry. Resume the game with the code activated. Note: Some codes may only be enabled once per game. Also, codes that have multiple tiers (for example, credits) only take effect when activated in order (lowest to highest).
Refill oxygen
Press X(2), Y(3).
Refill Stasis and Kinesis energy
Press X, Y(2), X, Y.
+2 Nodes
Press Y, X(3), Y.
+5 Nodes
Press Y, X, Y, X(2), Y, X(2), Y, X(2), Y.
+1,000 Credits
Press X(3), Y, X.
+2,000 Credits
Press X(3), Y(2).
+5,000 Credits
Press X(3), Y, X, Y.
+10,000 Credits
Press X, Y(3), X(2), Y.
Completion bonuses
Successfully complete the game and save it. Continue on your cleared saved game file to get the following bonuses.
Ten Power Nodes
50,000 credits
The back story log entries
Impossible difficulty setting
Level 6 Military suit schematic
Defeating the final Boss
Do not be intimidated by its size. Though massive, it is very easy to kill. The following was done under the Medium difficulty setting. Upon starting the fight, notice you are "caged in" by the Boss' tentacles. Notice the yellow "blooms" around the Boss' mouth. Shooting each one will get you closer to killing it. However, upon shooting a few of them, the boss Grabs you, holding you in the air. During this time, it appears that you are helpless. Aim whatever weapon you are using at the time and shoot the yellow blooms. After a few shots you will be dropped. The Boss will then begin slamming its tentacles at you more frequently. They are very easy to avoid. Strafe left to right constantly. They will never hit you. The Boss will roar, shoot a few exploding cells at you, or will drop enemy pods upon you. This is part is also easy, considering it is usually only two small Necromorphs. After you destroy the blooms, you will notice a "caged" area underneath the beast. Under this rib cage lies its many hearts. Again, use same strategy with the whole tentacle scenario. After a few times, the Boss will have his fit and open up again. Unload and the Boss will come tumbling down.
Finding the Peng Treasure
You must be on the flight deck on Chapter 13. When in the flight room where your ship "used" to be, look between the walkways. You should see a statue. Pick it up with kinesis, and you will get the Peng Treasure. It can also be sold for 30,000 credits.
Hidden message
Take the first letter of each chapter and arrange them in order to spell out the sentence "Nicole is dead".
Secret message key
In Chapter 1, just after you repair the claw for the tram, hit your objective finder. Follow the blue line into the hallway where you need to go. Stop as soon as you enter the hallway, and look up at the catwalk above your head; ignore the alien for now. Walk until you find the first corridor on the right. Walk in there to see writing in an alien language all over. Look down to see a message in English that reads "Don't listen to their lies, read what they're really saying." Keep reading to find a key that shows the alien language, and below that English letters from A to Z and 1 through 0. Although not everything will be legible, you should be able to decipher enough to understand what is written.
Wear Military suit in Impossible mode
Successfully complete the game in New Game Plus mode with the Military suit bought and equipped, and save the game immediately before the final Boss. Once the game ends and the credits begin, skip them, and do not save the game when prompted. Instead, immediately start a new game on the Impossible difficulty to start with the Military suit.
Cheat mode...