Wall jump:
If there is a wall is to your right, jump up and to the right, then jump off the wall to your left.

Agility power-up:
When your adrenaline reaches 100 and it starts to flash, quickly tap Down(3), Up.

Get shot into the air:
If you are on an elevator going up, jump at the top. You will get shot into the air. On a certain capture the flag level, you can get to a secret area by doing this.

Regeneration power-up:
When your adrenaline reaches 100 and it starts to flash, quickly tap Down(4).

Invisibility power-up:
When your adrenaline reaches 100 and it starts to flash, quickly tap Right(2), Left(2).

Cursed level secret
When you are in the swamp near the skull that's on the base of the wall there is a lift taking you to the top of the level where you will find some wooden beams to walk across. There is a gap in the middle which you must jump and then continue along the wooden beam to what seems like a wall. Carry on and you will disappear through the wall where you will find some goodies(tip, This is a great place for camping when playing split screen with your mates, Just wait for them to come near and surprise them from nowhere).

Combo with the shock rifle
To do a powerful combo attack with the shock rifle use the secondary fire which is the ball of energy and then when it is near your desired target fire the primary fire at it and watch them all die!

Berserk power-up :
When your adrenaline reaches 100 and it starts to flash, quickly tap Up(4).