Getting the Red Key

On the Rooftop, grab the Pistol Ammo behind the crate. Shoot the fan and drop down.

You will land on a Large Medikit on The Street. Turn right and kill the Trooper on the box. Grab the Large Medikit beside the box. Shoot the window of the building you are facing to kill the Trooper inside. Jump onto the box, then onto the building's ledge.

From the ledge, jump to the higher ledge under the "innocent" sign for SECRET 1. Walk to the indentation and take the RPG that rises. Return to the lower ledge.

For SECRET 2, jump from the ledge into an invisible window on this side. Inside, find a monitor and RPG Ammo on the bed. Kill the Trooper in the dark. Open the "Biker Bimbo" poster to find Steroids in the new room.

Back on The Street, jump out onto the ledge. Kill the waiting Trooper. Proceed down the ledge and take the Atomic Health. Kill the Trooper across in the darkness. Jump off the ledge. Find Pistol Ammo in the garbage bin. If you go near the no parking sign, a Trooper will spawn in the bin.

To enter The Foyer, shoot an RPG rocket at the Trooper in the ticket stand. This blows up the cracked wall. Kill the Captain inside by staying in the booth. Use your RPG to kill the Pig Cop hiding behind the column.

Open the door to The Snack Stand. Kill the Pig Cop at the till with an RPG blast, or run over the booth and open the door on the right. Take the Shotgun inside and kill the Trooper. Then, kill the Pig Cop and any other Troopers. Use the counter as cover (press the cover button to crouch behind walls or objects) for enemies not on your side. A door opens on the other side of the till, leading to an Atomic Health, but beware of the Pig Cop inside.

For SECRET 3, after clearing the room, touch the cash register to open a secret door. Go under this area and touch the wall underneath the far right to make a small elevator rise, allowing you to get Body Armor.

For SECRET 4, jump onto the trash can near the "Arcade" sign and open the wall. Inside, find Pipebombs, a Small Medikit, and Night Vision Goggles.

Go to the hallway closest to the counter and follow it to The Bathroom. Kill the two Troopers and the Captain. Find Shotgun Shells behind the couch. Open the right door and kill the Trooper on the toilet. Jump onto the top of the stalls to find a Portable Medikit.

Go into The Vent. Shoot an RPG at the corner to reveal a part with a Holoduke.

For SECRET 5, go to the end of the vent. Kill the Trooper inside the vent, being careful of the babe. Kill the two other Troopers and grab the Shotgun Shells.

Open the door to The Film Room. Use a Pipebomb to clear out some of the four Troopers. Kill the Captain, Trooper, and grab the RPG. Get the Red Key from the counter in the back. Find Steroids here as well. Go down the stairs to kill a Trooper and a Pig Cop for an earthquake and a crack in the wall with a Large Medikit. Jump onto the movie projector to get Atomic Health, which opens a door beside it.

SECRET 6 contains a Trooper, a Captain, and an RPG.