Completion bonuses
Successfully complete the game to get approximately 3,000,000 DNA and have ammunition recharge for your non-selected weapons.
Destroy All Humans! reference
Go to the Space Dust in Las Paradiso. Look closely at the movie posters to find an ad for the original Destroy All Humans!
Mario, Sonic, and Halo series references
When you do the first story mission in Belleville, France, Pox will start talking about video game ideas. Crypto will say, "You're a plumber, but you don't use plumbing stuff to kill your enemies, you just jump on them" (a reference to the Mario series),
"You're a really fast hedgehog" (a reference to the Sonic series), and "You're a space marine on a planet with a ring around it" (a reference to the Halo series). Pox will say all those ideas suck and then makes up his own idea.
Cheat mode
At the "Extras" menu, select the "Unlock Content" option. Enter one of the following codes to unlock the corresponding bonus. Then, select the "Customize" option at the "Options" menu to activate the unlocked bonus.
Saucer attachments
Enter "V81fvUW3" as a code to unlock the Saucer attachments.
Saucer skins
Enter "X91mw7zp" as a code to unlock the Saucer skins.
Biker costume
Enter "1gb57M2x" as a code to unlock the Biker costume.
Chef costume
Enter "51c24KiW" as a code to unlock the Chef costume.
Gangster costume
Enter "J5d99bPz" as a code to unlock the Gangster costume.
Kung Fu costume
Enter "Ly11r98H" as a code to unlock the Kung Fu costume.
Mime costume
Enter "7qd33J1n" as a code to unlock the Mime costume.
Velvet costume
Enter "F9sT5v88" as a code to unlock the Velvet costume.
Seventies costume
Enter "S63bf2kd" as a code to unlock the Seventies costume.
Sixties costume
Enter "M13Ni95L" as a code to unlock the Sixties costume.