Portal 2

Successfully complete the game.

Complete the indicated task to unlock the corresponding item for purchase at the store.

Bionic Beanie: Complete "Lunacy".
WCC Flag: Complete "High Five".

During your escape with Wheatly you will eventually run into the 'Bring your daughter to work day' room. Which has all sorts of different science fair Potato projects. If you go down to the very end of the line you will find the over grown potato. Look closely You will find the owner of the project has written her name on one of the bottom corners. Why, it's Chell!

In the first test chamber, after discovering white gel (where it comes down from a pipe infinitely), if you stay in the chamber for really long time (about 10 minutes or so), Cave Johnson will reveal secrets about Caroline and GLaDOS in a long monologue.

While attempting to earn the "Ship Overboard" achievement or trophy, once you enter the door behind the filing cabinet there are three metal doors in the hallway. If you activate the doors. Cave Johnson talks about the tests. Activate all three doors and the achievement or trophy will be unlocked.

Play Chapter 2 "Test Chamber 6". Get the radio that appears in a clump of garbage into a window above the chamber after you hit a button. Work your way back through the level and place a portal on the pad across from the window. Use the launchers to get through the portal and into the room past the window, with radio in hand. Take the radio up to the wall to earn the trophy.

Play Chapter 5 "The Escape" and reach the conveyor belts carrying droids to the incinerator. Use a portal to get onto the conveyor belt. Walk on the belt until a droid with a working laser beam appears. Pick it up to earn the trophy.

Play Chapter 9. After Wheatley's surprise, portal away from the platform just as Wheatley sends arms to crush you. Do not run away on the catwalk. Stay nearby and Wheatly will beg you to come back. Stand at the edge of the pit overlooking his trap. He will ask you to just jump in the pit. Jump in to earn the trophy.

Play Chapter 2 "Test Chamber 7". Keep track of the Companion Cube in this chamber. You can return to get it at the end of the level after using it to depress the button. Ignore GLadOS's comments and carry the cube through the broken "Emancipation Grill" at the end of the chamber to earn the trophy.

Play Chapter 6 "The Fall" and reach the 1958 "28" room. There is a cube is trapped in a glass box and Blue Gel streaming out of a pipe in one corner in this room. Save the game. Shoot a portal under the Gel and over the crate to coat the cube. The cube will bounce until it breaks the glass. It will eventually break out of the glass. Catch this cube before it touches the ground to earn the trophy. Note: Try standing between the entrance and the gel spout.