Destroy All Humans!

It you levitate a person for a long time, they will die.

When you are in the form of another person, to make you brain juice meter go down, read other people's thoughts.

Stand in an open area on any level and walk forward. Keep decreasing your speed until you eventually begin walking in place.

Halfway through the game you will experience a level where you go to the drive-in to switch films with the one that is showing. Watch what is showing before you switch films to see that the film is Edward D. Wood, Jr.'s Plan 9 From Outer Space.

Allow the game to idle at the mission selection screen and Pox will make various remarks.

Find the monument, then throw cars at it until it breaks into two pieces. Get on the long pointy piece, PK the middle, and try to stay on.

After getting out of your UFO, aim at a human and press Y. When you have changed into the human, the bar on the top left corner of the screen will go down. When it is all gone, you will change back into an alien. If you want to remain human, turn into a human and while walking around, scan other humans or animals to make the bar on the top left corner stay up.

Enable the "Bulletproof Crypto", "Ammo-A-Plenty", and "Deep Thinker" codes, then get all of Crypto's upgrades. After this you can turn into a human and walk around TK'ing everything.