Secret 1: Hole in the canyon wall
When the level first starts, you can go through the IMF door, or you can go to the other side of the rock canyon. If you jump up on it, and make your way back above where you started, you will see a small, and rather narrow ledge. Follow the ledge around the canyon, and you will come to a cavern. Inside it is a Holoduke and some pipe bombs, as well as one of the turrets that was shooting at you when you were at the start (Note: No Turrets are present out here on Piece Of Cake). It can be pretty dark in here, and it is easy to fall off on your way up here.
Secret 2: Bloody handprint
If you go up on the ledge in the start of the level, and walk around on top of where you started the level, you will see a red hand on the wall. Hit it.This will open up a door below you, and behind your initial starting spot in the level. Jump off the ledge, and head in there. Once inside, you will see a red room with an Atomic Health inside. Go in there to claim the second secret of the level.
Secret 3: Behind the walk-in freezer
The third secret is in the mess hall area. Once you clear out all the enemies, make your way into the back - you will see a silver door leading to the meat locker. Go in there, and take out an Octabrain in close quarters!. Once you've done that, hit the red hand on the wall. Doing that will open up another room with a forcefield and a computer. Using the computer will give you access to the next room, the one with a Shrink Ray and some armor, as well as the third secret. From here, you can either backtrack to get back to the kitchen, or you can jump into the water here, and swim back to the sink in the kitchen (this is the shorter path).
Secret 4: Elevator in the barracks
The fourth secret is in the barracks area of the level. There's a bunch of pig cops to take out first. Once you do that, make your way to the bed towards the back of the room that has steroids sitting on it. Stand on the bed, and "use" the wall. The bed will raise into the ceiling, taking you with it. It will reveal a path you can take to get to a door. Open it, and a room will be revealed with a Jetpack and some Devastator ammo.
Secret 5: Above the bathroom stall
The fifth secret is in the bathroom. Above the sink is a switch that looks like a hand dryer. Flip it, and a compartment will open up above the toilet. Jump up there and head in to get the fifth secret, and a medkit.
Secret 6: Compartment with the RPG
The sixth secret is the room where you get the red key. Next to the picture of President Washington, there is a computer. If you use the computer, it will open up a door on the other side of the room with a pig cop behind it. Take out the pig cop. Once the pig cop is taken out, go into the room he was in. There is an RPG in there, as well as the sixth secret. The game prints the word "Unlocked" instead of "A Secret Place!" when you go into this secret because it unlocks a secret door on the wall, which connects to the fourth secret area, that was previously locked if you went to secret four first. This is also an easy way to get the fourth secret without needing to fight your way through the barracks at all, and getting both secrets together.
Secret 7: Mine car
The final secret is in the middle of the Get Smart reference (The Sequence where all the doors open towards the end of the level). After the second door, you will see a vent up near the ceiling. Kick or shoot the gate, and head in the vent. There is another gate at the far end, kick it or shoot it and then head out. There's some enemies in here waiting for you; take them out. You will see a switch here. Flip the switch, and it will allow you access to the mine car. Go into the mine car to get the seventh and final secret for this level. While it isn't part of the secret as such, you can also go through the door that says "Under Construction", and make your way past an Assault Commander and a few other enemies to get a Devastator. (Assault Commander is not present in Piece of Cake difficulty)
- The entrance of the building says "IMF" above the door and "Improbable Mission Facility" on a nearby sign. This is a parody of the Impossible Mission Force from the Mission: Impossible series.
- The music on this level closely resembles the Mission: Impossible theme.
- In the room with the Red Access Card, there are monitors showing something that resembles a comet. In reality, these are actually screenshots of a burning fuse from the 1960s TV show Mission: Impossible.
- Beside the TV in the barracks, there is a magazine with a golden ring on a pink background on it. The inscription reads "Moger Roore", which is a reference to actor Roger Moore, and the golden ring is possibly an allusion to Goldfinger, the third movie in Eon Productions' James Bond series (however, in that movie James Bond was still portrayed by Sean Connery). It could also be a reference to the spy show, "The Saint" and is a halo. "The Saint" also starred Roger Moore.
- In the kitchen, use the "dnclip" cheat code to follow the flowing water in the tray return. You will come across a small message on the wall that reads, "ARE YOU SMALL OR ARE YOU CHEATING?"
- There is a tape recorder in the front room of the building. If the player interacts with it, the tape will play a recording of a 1950s-style broadcaster dramatically stating, "This tape will self-destruct in one second." One second later, the tape explodes. This is another homage to the Mission: Impossible franchise.
- In the briefing room, a "Steed" hanger with an umbrella and hat can be seen. This is a reference to the character John Steed from the old British TV show The Avengers.
- The white room with the booby-trapped ventilation shaft is an homage to the scene in the first Mission: Impossible film where Tom Cruise is suspended in mid-air and trying to steal government secrets from a computer terminal. The player can take a similar approach by using the jetpack. Touching the floor will trigger an alarm and cause enemies to attack.
- The sequence of doors near the end of the level is a reference to the opening of the 1960s TV show Get Smart.
- Just after the sequence of doors is a telephone that has "U.N.C.L.E" printed on it. This is a reference to The Man from U.N.C.L.E.. The elevator that is activated by using the telephone is another reference to Get Smart.
- Upon arriving in the storage room that requires the Red Access Card, move behind the box in the corner to read a message: "From: Wars of the World Prop Dept. To: O. Wells. Prop #45". This is in reference to the famous radio broadcast of H.G. Wells's The War of the Worlds which told of an invasion from Mars. O. Wells refers to actor Orson Welles who had directed and narrated the famous broadcast in 1938. This crate can be opened to reveal Expander ammunition. This may also be a reference to War of the Worlds because the firing sound of the Expander is the same sound effect from the 1950s War of the Worlds film by George Pal that is used by the Martian "heat rays."
- Using the "dnshowmap" and "dnclip" cheat codes, it is possible to find two out-of-bounds areas with hidden messages. With the map view open, enter the IMF building, and turn right. Continue out of bounds for some distance until you see two rooms to your left on the map. The first room is the news broadcast shown by the security camera elsewhere in the level. On the wall opposite of the newscaster, there is a message that reads, "Looking for secrets?" In a nearby out-of-bounds room, there is a message that reads, "C'mon, quit cheating!"
See Also: Duke Nukem 3D prototypes
Like all levels in The Birth, It's Impossible repurposed materials that were scrapped before the classic April 1996 release. In particular, scrapped parts from an early version of Warp Factor can be found on the final build of It's Impossible. The scrapped parts can be seen in footage of Warp Factor from May 9, 1995.