The Nightmare in Vegas level will open up to you once you find all of the secrets in the previous four levels.

Hotel Key-
From where you begin, turn to your left and then run forward and activate the switch on the wall. Now, enter the next room and then head to the right and walk through the next door on your right. Run into the hallway and then head to the left and walk over to the window on your left. Shoot out the window and then walk forward and drop down onto the platform below. Now, turn to your right and then jump across and grab onto the edge of the ledge. Shimmy to your left and then once you reach the end, climb down on the grip-able wall and up onto the next ledge. Head to your left and then jump across to the balcony and take out the two goons. Now, enter the hotel room and then run to your left and activate the switch on the wall. Enter the bathroom and then run into the shower and grab the Hotel Key from the floor.

Door Circuit-
Once you have the Hotel Key, leave the bathroom and then head into the room and exit through the next door on your left. Now, turn to your left and then use the Hotel Key on the lock to open the big doors. Enter the open doors and then run into the big room on your right. Now, run forward to a broken elevator and then turn to the right and look down into the room to find two small platforms sticking out of the far wall. Make sure that you heal yourself after each following step as you will be taking some damage making your jumps and drops. Walk around the room until the left platform is directly beneath you and then hang from the edge and drop down to the platform below. Now, turn to your left and then jump forward to the next platform below. Now, turn to your left and then jump onto the slightly sloping ledge next to the razors. Now, walk not run across the razors to the far side and then jump across to the starry platform. Once on the platform, walk over and grab the Circuit Board on the ground.

Elevator Junction-
After grabbing the Circuit Board, drop down to the ground and then run into the golden statue room. Run across the area to the pool and then place your Circuit Board into the door panel. Once the door opens, run outside and then head to the left and take out the Dinosaur running at you. With the Dino out of the way, run into the small alley on your right and then run to the square depression in the street and grab the Elevator Junction on the ground.

Completing the Level-
Now that you have the Elevator Junction, turn around and defeat the next Dinosaur that charges you. With the beast out of the way, return to the giant golden statue and look up until you see two small square platforms sticking out of the wall. Now, climb up the golden statue until you are next to the left platform and back flip onto the platform. Turn around and then jump up onto the next block and run up the staircase to the top floor. Run across the room to the broken elevator and then place the Elevator Junction into the machine. Now, activate the lift controls and summon the lift. Once it arrives, pull the switch again and then run into the lift when it arrives. Ride it to the top and then run out into the new hallway. Finally, head to the right and then take out the giant beast running towards you. Once you defeat the beast, the level will be complete!

Secrets-

Gold Coins-
After grabbing the Circuit Board, drop down to the ground and then run into the jailhouse room. On the stage are two openings in the jail cells. Pull the two blocks from the back of the room, into position and the grate behind them will open up. Climb over the blocks and then drop into the hidden room. Now, you'll have to push and pull the blocks in the area until you uncover the gold coins!

Gold Bars-
After grabbing the Circuit Board, drop down to the ground and then run into the golden statue room. Run across the area to the pool and then place your Circuit Board into the door panel. Once the door opens, run outside and then head to the left and take out the Dinosaur running at you. With the Dino out of the way, run into the small alley on your left and enter the Dino cage on your left to find the gold bars!

Gold Skull-
Now that you have the Elevator Junction, turn around and defeat the next Dinosaur that charges you. With the beast out of the way, return to the giant golden statue and look up until you see two small square platforms sticking out of the wall. Now, climb up the golden statue until you are next to the left platform and back flip onto the platform. Turn around and then jump up onto the next block and run up the staircase to the top floor. Run across the room to the broken elevator and then place the Elevator Junction into the machine. Now, activate the lift controls and summon the lift. Once it arrives, pull the switch again and then run into the lift when it arrives. Ride it to the top and then run out into the new hallway. Finally, head to the right and then run all the way down the hallway and into the Yeti cage to find the gold skull!