Alternate main menu
Successfully complete the game to change the background of the main menu.
Intel at no cost
Purchase all the intel when a mission starts. Make a not of it, then pause game play 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.
Newspaper headlines
After completing a level, the newspaper information varies 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. High accuracy states you are a well trained marksman. Try doing the level differently to see different headlines.
A New Life: Easy "Silent Assassin" rank
Start the mission with no weapons except for your standard equipment. First, go to the back of the food truck when the delivery man is walking off. Pick up the donuts then take them around the corner so that nobody can see you. Put them on the floor and then scroll through your inventory. Go to the "Sedative Syringe", and select it. Look down to the donut box, then inject the sedative into them. Pick up the donuts again, put the syringe away, then go back to the food truck. Drop the box of donuts on the floor directly behind it. Walk away. The delivery man will pick up the donuts and take them to the FBI van across the road. Wait a short time. An short intermission sequence inside the truck will appear, showing the FBI agents falling asleep. Go to the back of the truck, open the door when prompted, and go inside. When inside the FBI truck, suit up as an FBI agent, and steal the video tape, which should be on the left side of the van as you go in. Do not pick up any weapons. Leave the vehicle. Go up to the front of the house and walk inside. Go out the back towards the shed, which is in the top right hand corner. Wait until there is nobody around. If the pool man goes in, do not be tempted to follow him or your suspicion bar will go into the yellow. When there is nobody around, pick the lock, go inside, and pick up the lighter fluid. Leave the shed, go right, and then go towards the pool. Over to your right is a barbecue. Go up to it and you will get the "Rig the Barbeque" option. Select I, then go inside the house and wait under the stairs. Stand around for a short time. A short intermission sequence will show a woman being burned alive. When she is dead, go back outside and pick up the microfilm that she is wearing around her neck. Go back inside then go up the stairs. Turn right across the landing, then go straight. Open the first door on your right. Go in and wait behind the L-shaped wall. If the main target is already there, wait for him to leave, then wait awhile for him to return. When he returns, make sure he has his back towards you then fibrewire him. When he dies, drag his body to the place you were hiding (the L-shaped wall). Then, sprint out of the house towards your escape as quickly as possible. If done in a short time, you should get either a "Hitman" rating or "Silent Assassin" rank. Either way, you will get $100,000 and if you have already completed the game you can purchase an additional upgrade to your custom weapons whenever you select a mission.
Requiem: Control ending
Requiem is the last level. Allow the credits to play all the way through. 47's body will be lowered underground. This level is playable. As the credits are playing, you can hear 47's heart beat and his health bar moving to the rhythm of his heart beat. As the credits are playing, repeatedly tap [X], [B], [A], [Y], [L], and [R] in any order. This must be done quickly. You will notice that his heart begins to beat faster and that his health bar rises. When his health bar reaches full, he will rise up and you will have control of him. The objective is to leave no witnesses -- kill everyone.
Alternately, move the [Left Analog-stick] when Agent 47 is on the grave while the credits are running.
License plates
Look at the license plates of cars on different levels. On "A New Life", the suburbs, the license plate of all the cars reads BADBLOD (Bad Blood). On "A House Of Cards", the casino, the license plate of the first limo reads "L1MONEY", or something similar.
Upgrades
SP12 Shotgun
Butt stock ($50,000)
Flechette ammo ($50,000)
Extra ammo ($75,000)
Reload boost ($75,000)
12 gauge slugs ($75,000)
Short barrel ($100,000)
Rail mount ($100,000)
Laser sight ($150,000)
Bigger magazine ($150,000)
Red dot sight ($200,000)
Silencer type1 ($200,000)
M4
Ris handguard ($50,000)
Low velocity ammo ($50,000)
Butt stock ($50,000)
Extra ammo ($75,000)
Laser sight ($75,000)
Rail mount ($75,000)
Armor piercing bullets ($75,000)
Silencer type 1 ($100,000)
Pistol grip ($100,000)
Double clip ($150,000)
Red dot sight ($150,000)
Silencer type 2 ($200,000)
Drum magazine ($200,000)
Scope type 1 ($200,000)
Silverballer
Low velocity ammo ($50,000)
Silencer type 1 ($50,000)
Extra ammo ($75,000)
Laser sight ($75,000)
Rail mount ($75,000)
Magnum ammo ($100,000)
Dual action ($100,000)
Long slide ($100,000)
Red dot sight ($150,000)
Large clip ($150,000)
Silencer type 2 ($200,000)
Full auto fire ($200,000)
Scope type 1 ($200,000)
SMG Tactical
Butt stock ($50,000)
Low velocity ammo ($50,000)
Extra ammo ($75,000)
Rail mount ($75,000)
Magnum ammo ($75,000)
Rapid fire ($100,000)
Short barrel ($100,000)
Silencertype 1 ($100,000)
Laser sight ($150,000)
Double clip ($150,000)
Silencer type 2 ($200,000)
Red dot sight ($200,000)
Misc. upgrades
Pain killers ($50,000)
7x50 zoom binoculars ($50,000)
Improved lockpick ($50,000)
Kevlar vest ($75,000)
Enhanced detonator ($75,000)
Adrenaline ($100,000)
Flak vest ($100,000)
Extra mine ($100,000)
Cratt Schultz lockpick ($150,000)
Foil padded suitcase ($150,000)
Flexible flak vest ($200,000)