Hollywood Holocaust is the first level of Duke Nukem 64. It is largely unchanged from the original Hollywood Holocaust in Duke Nukem 3D, but it features some notable modifications, particularly involving the secrets and outdoor areas.
Hollywood Holocaust is considered Level 0 according to the game's level numbering scheme. It is followed by Gun Crazy.
There are 13 secrets on this level.
Secret 1: Vitamin X Compartment
After dropping from the rooftop into the outdoor street area at the beginning of the level, jump onto the box on the right, and then jump onto the ledge on the building beside you. Two of the windows along this ledge are faux windows; they can be entered without even opening them. In the room inside these windows, a section of the wall to the right of the Shadow Warrior graphic can be opened, revealing a secret compartment with Vitamin X inside.
Secret 2: Pipe Bombs Near The Elevator
At the bottom of the elevator inside the movie theater, jump onto the plastic trash can beside the elevator. Pressing the "use"/"open" button on the controller while facing the wall will open a compartment above you. Jump into this secret compartment to retrieve some Pipe Bombs.
Secret 3: Cash Register
Go behind the snack counter inside the movie theater. Press the "use"/"open" button on the controller while facing the cash register. A secret compartment will open high above you in the wall to the right, outside the snack counter area. While standing against the wall beneath this secret compartment, pressing the "use"/"open" button again will cause an elevator to lift you up to the compartment.
Secret 4: Behind The Snack Counter
While inside the secret compartment from Secret 3 above, a switch on the left-hand wall will cause a secret room to open behind the snack counter.
Secret 5: Portable Medkit In The Bathroom
Jump on top of the stalls in the bathroom, and you can find a secret area containing a Portable Medkit on the right-hand side.
Secret 6: Holoduke In The Ventilation Shaft
Entering the ventilation shaft above the stalls in the bathroom, a destructible section of wall can be found at the right-hand turn inside the shaft. Destroying the wall with a Pipe Bomb or with the Grenade Launcher will reveal a secret Holoduke inside.
Secret 7: Captive Babe Behind The Projector Room
Continuing to the other end of the ventilation shaft from Secret 6 above, you will find a secret room with a captive babe inside. One of the walls of this room can be opened into the projector room. It can also be accessed by opening the back wall of the projector room.
Secret 8: Inside The Projector Room
In the projector room, jump on top of the projector and retrieve the Atomic Health. This will trigger a secret compartment to open beside the projector.
Secret 9: Large Medkit In The Stairwell
At the bottom of the stairwell leading to the projector room, a section of the wall can be opened to reveal a secret Large Medkit inside.
Secret 10: Apartment Above The Movie Theater
Upon reaching the bridge before the exit button, you can find a small ledge below the bridge that leads around to the front of the movie theater. You can jump onto the very last palm tree along this ledge, and then you can jump from the palm tree through some faux windows above the movie theater entrance (the second row of windows above the ledge). Alternatively, you can just use the Jetpack if you have it. Inside, you will find a secret apartment full of weapons.
Secret 11: High Above The Bridge
Upon reaching the bridge before the exit button, use the Jetpack to reach a secret crevice high above the doors below. (A Jetpack can be found on this level by opening the movie theater screen using the switch inside the projector room and then detonating a hole in the movie screen.)
Secret 12: Convenience Store
To the right of the exit button, a light section of wall can be opened to reveal a teleporter. This teleporter will take you into a hallway behind the convenience store. Open the door in this hallway and enter the secret shopping area of the convenience store.
Secret 13: Compartment In The Convenience Store Office
In the office behind the convenience store (reached via Secret 12 above), open the middle shelf of boxes in order to reveal a secret compartment.
There is only one babe to rescue on this level.
Babe 1: Behind The Projector Room
The only babe on this level is in the secret room behind the projector room. She can be reached either by opening an unmarked wall at the back of the projector room or by crawling through the ventilation shaft above the stalls in the bathroom.
Changes from Duke Nukem 3D
This level begins identically to the original Hollywood Holocaust in Duke Nukem 3D. However, there is now greater detail to the out-of-bounds areas surrounding the starting rooftop and surrounding the main street below. Many buildings and palm trees are visible outside the walls. As a result, Duke's Skycar now crashes into a fully rendered 3D building.
The first enemy of the level now stands on top of a car crashed beneath a "No Parking" sign, instead of atop the box right next to it. In the 20th Anniversary Edition developer commentary, the developers note that the car in the Duke Nukem 64 version of Hollywood Holocaust was derived from a similar car found on Pigsty.
The movie featured on the sign above the front entrance of the movie theater is now titled "Uranus Attacks" instead of "Attack of the Bleached Blonde Biker Bimbos". Where there was previously a single palm tree, there is now an entire row of palm trees running along the main street.
A convenience store entrance is now situated on the main street, in the corner behind the dumpster fire. The store entrance is locked from the outside, but the store can still be accessed via a secret teleporter hidden in the wall to the right of the exit button.
Inside the movie theater, a UFO film is playing instead of the stripper film. Drinks from the concession stand are now littered on the ground beneath the seats.
Notably, earthquakes no longer occur on this level. This is unusual because comparable explosions in other parts of the game, such as the final hallway in Lunar Reactor, have not been removed.
Smaller changes include a remodeling of the concession stand, a complete restructuring of the bathroom area, and a reordering of the game machines in the arcade.
Lastly, many of the secret areas on this level have been modified. Those changes are described above in the "Secrets" section on this page.
The developers initially had plans to render mirrors on the Nintendo 64 but ultimately abandoned them. A remnant of some early experiments can be found on this level by using the no-clip cheat to pass through the first shattered mirror on the left-hand side upon entering the bathroom. A partially mirrored version of the bathroom exists on the other side, though it looks like the developers never finished it. For some reason, this area was not removed from the final game.