Successfully complete any mission and earn as little money as possible. Save the game, then replay that mission again. Earn as much money as possible and create a save point immediately before escaping from the level. Then, escape from the level and the mission review screens will appear displaying your new account balance. Any additional money earned from playing the mission the second time will be added to your account balance. Next, press B to return to the first screen, then press Y replay the mission. A message warning that your progress will be lost will appear. Ignore this message, as your save points and account balance will not be reset. When the mission begins again, load the save point created immediately before escaping from the level. Escape from the level and the additional money will be added to your account balance again. Repeat this process as much as desired to get an unlimited amount of money.
Infinite saves in Normal and Expert mode
While saving during a mission on the Normal or Expert difficulty setting, press Start before the “Save Complete” message appears and it will not count towards your limit of saves. Note: This will not harm your saved game.
Purchase all the intel when a mission starts. Make a note of it, then pause the game and choose to restart the mission. You will have your original starting money, and the intel will now be available for purchase again even though you know what it contained.
Successfully complete the game to alternate the main menu background.
After completing a mission, the newspaper headline will vary depending on how you did. If you did poorly, the paper will say so in the paragraph. If you shoot very little and use mostly hand to hand it will say that there is not enough information to make a ranked description of you. If you completed the mission with high accuracy, it will state that you are a well trained marksman. Try completing missions differently to see different headlines.
Look at the license plates of cars in different levels. In the “A New Life” mission, the license plate of all the cars reads BADBLOD (Bad Blood). In the “A House Of Cards” mission, the license plate of the first limo at the casino reads “L1MONEY”, or something similar.
Alternate ending sequence
In the final level “Requiem”, Diana will give you the antidote to the death serum. You will fade in and out of life (power bar rises and drops to the beat of Agent 47’s heart) while the credits roll. If you do nothing, the game will end. However, if you press the Left Analog-stick Up and Down (or any other buttons) repeatedly, you will come back to life and your mission will be to leave no witnesses.