Level 13: Unfriendly Skies

AntMag.NET

Alright, so you've landed yourself in an airport in Level 13: Unfriendly Skies. Doesn't look like a vacation spot, does it? Turns out, those Zilla goons have decided to make it their personal playground, and Lo Wang is right in the middle of it. Let's get you through this.

Secrets

This level's got a good chunk of secrets, so keep your eyes peeled. Some of these are pretty well hidden!

First up, head to the north side where the pachinko machines are. You'll see a switch nearby. Hit it, then hop on top of the machines. Duck into the opening above the far machine to snag some missiles.
After you grab the red key card from the airplane (yeah, the one past the pachinko parlor), find the elevator that needs it. Call it, then send it back down. Head back to the room with the phones, candy machine, and pop machines. Look above the candy machine – a hatch has opened. Jump up, go into the duct, and shoot out the grill at the end. Inside, you'll find some caltrops, a Portable MedKit, Riot Gun, and grenade shells.
Go back to that red access elevator and ride it down. Head west and up the spiral staircase to Impulse Gifts. Use the cash register, and a secret area will open up in the wall right across from you. Jump in and grab a fortune cookie.
Back down the spiral stairs, head south into the short hallway, then west and left into the baggage claim carousel. Go into the conveyor room until you see the Nin-Nin Airline banner. Turn around, face the conveyor, and you'll see a baggage chute. Jump in and walk up until you reach an open area. Watch out, this one's guarded by some Baby Rippers! Turn right (south) and you'll see the baggage compactor with a switch. Hit the switch, and a secret area opens to the left inside the compactor. It holds a Grenade Launcher and a Portable MedKit. Be quick, though – once you jump in, it starts compacting! Time your exit after it stops crushing for about 4 cycles.
After that, head back through the baggage conveyor to the baggage claim. As you head towards the exit, look for an air grill to the right of the hallway. Shoot it out, jump in from the edge of the carousel, and walk through the duct. Shoot out the grill on the other side and jump out. Turn right (south) and follow the path into Blue's Brews. Inside the bar, find the banner on the west wall, a bit up from the ground. Jump up and push it. A secret area opens to the right, revealing a room with a Rail Gun spinning in a Ying-Yang symbol.
Now, head into the yellow access door to the control room where you get the blue access card. Inside, you'll see a pop machine on the west side. Jump on it, then turn to face the room. Look for a red button on the side of the radar panel in the center. Shoot it, then turn back on the pop machine and duck into the secret area that just opened. You'll find the Ripper Heart inside.
For the final secret area, which leads to the Auto Maul secret level, go back to the red access elevator and ride it to the main level. Walk out, hit the call switch to send it back down, and quickly hop onto the elevator before the door closes. Turn north, jump up, and hit the switch to send it back up. Now, turn south, walk into the duct, and grab the Nuclear Warhead. Just past it is the entrance to the secret level Auto Maul.