Half-Life 2

In the same area as the "Sore thrat Vortegaunt", trick ramp onto the land so the checkpoint triggers. Then, park under the grate. The combine should start shooting. Run back andvisit the Vortagaunt, then run back and the Combine will not shoot. Go back and ramp up there again and they should be dead on the ground.

When you reach the warehouse with the ramp in the bigcircular area go to your left. You should see two sewer pipessticking out from the wall. Park the boat under the left one andget on the boat by jumping. The cover will be pulled back so thatyou can crouch jump into the pipe. There are lots of toxic waste;you must sprint run down the pipe and it will get a little lighter.Turn left and you will go through a gap in the busted pipe. Thereis a Vortegaunt coughing and roasting a Headcrab on a fire. Thereis also health here.

When you begin the Ravenholm sequence, kill all the zombies but try to leave the explosive barrels intact. When that is done, do not go into the buildings but instead look at the tree. There will be a pair of zombie legs dangling from a branch by a wire. Enable the god code, take the Gravity Gun, pick up a barrel, and stand close to the legs. Fire the barrel at the legs, at point-blank range. You will hear a thudding noise. Move back slightly and enable the flashlight (if it is not already on) to see the legs making erratic movements and even scribe full circles around the branch.

After climbing over the white cars and going through the window, you will go in to a room that has two windows and a zombie in it. When you climb out the window, you will see the old man with a shotgun in a window. Proceed to your left on to a concrete ledge. You will see a flammable barrel behind a grate. Shoot at it and the grate will blow out. Hidden back behind the grate is health and ammunition.