Anytime during gameplay hold L1 + R1 + R2 + Select and press X, circle, square, triangle, X, cricle, square, and triangle.

Quake is a greaaaaaaat game man!!
Heres some cool hints!
don't be fooled the machine gun is actually quite a good gun.
You don't win Vadrigar, even when you defeat him.
The rail gun is hard to master. a good way to use it is either extreme close combat or if you are high and dry from everyone and you zoom in and shoot.
Also the grenade launcher, it is really quite pants! don't waist your time. its best to use as if it were a rocket launcher, make sure the grenade hits someone because in contact it explodes.
On the last LAST leval 'the keep' you will win 2 characters.
thats all i got 4 now.
trp in the house!