Portal 2 Easter egg guide: 30 secrets and references you may have missed

For a supposedly “short” game, Portal 2 takes a long time – a long time to truly complete and fully appreciate, anyway. Did you blast through in less than a week? Then you may have missed some of the greatest, cleverest, loveliest, Valve-iest moments… as well as the chance to unlock a lot more Achievements or Trophies.

Not to worry. Here’s our guide to every Portal 2 Easter egg, secret and hidden reference we could find, in order of appearance so you can go back and experience them all for yourself.

Know of any others? Tell us in the comments.

Hotel painting

Chapter 1, Introduction

You’ve definitely seen this already – Aperture Science requires you to “stare at art” for “intellectual sustenance” during the tutorial – but stare a little closer when you wake up the second time. The painting’s not only darker because the room has grown darker. Based on the presence of the moon in the sky, the painting has somehow transformed from a day scene into a night scene.

Chapter 1, Introduction

Wheatley hauls you through the crumbling facility so quickly that details of your environment can get lost in the blur. Take a moment, however, to read the creepy information plastered across the other test subjects’ rooms. Some are male, others female. Some are short and fat, others tall and thin. Most are adults, though the option for child exists. All are expired.

Chapter 1, Test Chamber 4

Remember “the cake is a lie” from Portal 1? Of course you do. That famous phrase was scrawled on the wall by Doug Rattman, a former Aperture Science programmer who witnessed GLaDOS’ initial attack on the facility and then survived on cans of beans while hiding out in various test chambers and maintenance areas. This is the first and easiest to find of his hideouts in Portal 2.

Rat Man Den #2 (with secret song)

Chapter 2, Test Chamber 3

Rat Man’s second hideout is much more elaborate, with two of his trademark murals painted on the walls. Even cooler, though, is the radio tucked away in a corner – it’s the only place in the game you’ll hear a song written and composed specifically for Portal 2, The National’s “Exile Vilify.” Available on the soundtrack, you can also listen to it (over and over and over) right here:

Rat Man Den #3 (with Rat Man’s final transmission)

Chapter 2, Test Chamber 6
Unlocks “Final Transmission” Achievement / Trophy

This isn’t the last of Rat Man’s hideouts you’ll encounter, but it may have been the last hideout he ever created. Grab the radio out of the trash that GLaDOS drops in this chamber and, as demonstrated in the video above, take it to Rat Man’s secret office near the ceiling. It’ll emit a mysterious screeching noise that, when decoded with special audio software, creates an image of a Companion Cube… on the moon?!

Also, listen carefully to the radio before you take it to Rat Man’s den. Sound familiar? That’s right – an instrumental jazz version of “Still Alive”!

Smuggle a Companion Cube

Chapter 2, Test Chamber 7
Unlocks “Preservation of Mass” Achievement / Trophy

GLaDOS specifically forbids you from taking anything out of this room, so of course you have to try, especially with a broken Emancipation Field at the exit and an adorable Companion Cube on the line. Watch the video for exactly how. Spoiler alert: GLaDOS isn’t amused.

GLaDOS quotes Moby Dick

Chapter 2, Test Chamber 8

In this room, GLaDOS provides helpful instructions on solving the puzzle – in true GLaDOS fashion, however, she provides these instructions at such a fast speed that no human could possibly hear what she’s saying. Fortunately, we have computers at GamesRadar. Unfortunately, when slowed down her advice isn’t actually helpful at all, just a random quote from the opening of Moby Dick: “And methodically knocking people's hats off – then, I account it high time to get to sea as soon as I can.”

Play the video to hear for yourself. For context, here’s the book.

Next page: Hidden farts, secret developer commentaries and a turret with way too much information…