Spoiler
The first secret is in the vents after exiting the broken elevator, after turning the first corner and just before turning in the next one, you´ll see a brighter galvanic pannel with some blood stains. You can break it.
The second one is in the storage room. One of the shelves that are against a wall can be opened.
The third secret is in the last section of the casino -just after exiting the cashier office- One of those purple cascades (at your left, when facing the exit) is a bit darker, and you can walk through it.
The fourth secret is at the back of the 1998 garbage truck, but it has its trick.
Finally the fifth one is the vent on the Slick Willy´s roof. That one was initially intented to be a sideway to enter the bar but then i changed my mind because i wanted people to visit Stratosfear.
The first secret is in the vents after exiting the broken elevator, after turning the first corner and just before turning in the next one, you´ll see a brighter galvanic pannel with some blood stains. You can break it.
The second one is in the storage room. One of the shelves that are against a wall can be opened.
The third secret is in the last section of the casino -just after exiting the cashier office- One of those purple cascades (at your left, when facing the exit) is a bit darker, and you can walk through it.
The fourth secret is at the back of the 1998 garbage truck, but it has its trick.
Finally the fifth one is the vent on the Slick Willy´s roof. That one was initially intented to be a sideway to enter the bar but then i changed my mind because i wanted people to visit Stratosfear.