[Joshy]

Its not that much.... joking
Defeating The Boss
In order to fight the Boss, you have to eliminate all of the hitmen. This will make the Boss battle much easier. When you have killed all of the hitmen, enter the confession room on the left. This is the one that you pray in during the first level;s loading screen. The priest will be in the confession room directly next to you, being held captive by the Russian general. The only way to get the general out is to crouch down and shoot a bullet at the heart on the confession booth's inside wall. A short intermission will start and the general will come out, firing an SP12. Use any automatic rifle and fire, making sure every bullet connects. Make sure you have the full amount of ammunition equipped in the gun. He should die within a few seconds.

Gun Collection
Throughout all the levels you will run into many different types of guns. Whenever you see a gun that you do not already have, pick it up. After you complete the level on which you found the gun, the gun will now be available at your house. You will have ammunition in the room for you to use if desired. However, there are many guns that are too big to carry inside your clothes and therefore must be held in the open. You will not be able to pick up a gun of the same size or greater without dropping the one you are holding. You will find other guns on the same level that you cannot pick up because you are already holding one, and the gun you want is simply too big to conceal. In this case, you will have to decide which gun you want more then finish the level with it. You can always replay that level to get the other gun that was left behind.

i dunno if this is hitman 2.....

Hint: Alternate ending sequence:
Successfully complete the last level of the game in campaign mode under the legendary difficulty setting. The new ending features a human and alien fighting hand to hand. The human will say "Its over", and then they hug because they know the explosion will kill them both. Also, the FMV sequence of each battle scene will be slightly longer.

Hint: Alternate dialogue:
Playing under the legendary difficulty setting introduces new dialogue not heard in other modes. For example, after being massacred by a force of Grunts, Jackals and Elites, one of the grunts asks, "Can I have his helmet?". Also, your fellow Marines seem to be a bit more chatty (as well as profane).

Glitch: No head:
On the first level when you get out of the tube, press X when prompted to exit the cryo tube. Watch your character get out. The screen will be white and coming into view. After you take control finally, turn and jump in the cryo tube before it closes. When you get in and it closes with you inside, you are stuck. When you cannot move in the tube and look up in a certain manner you will see yourself, but with no head.

There is loads of tips on Halo but too lazy to post it all here....