- Completion bonuses
Successfully complete the game to get approximately 3,000,000 DNA and have ammunition recharge for your non-selected weapons.

- Activate Cheats
At the 'Extras' menu, select the 'Unlock Content' option. Insert one of the following codes to unlock the corresponding bonus. Then, select the 'Customize' option at the 'Options' menu to activate the unlocked bonus.

Seventies costume Enter 'S63bf2kd' as a code to unlock the Seventies costume.
Saucer attachments Enter 'V81fvUW3' as a code to unlock the Saucer attachments.
Gangster costume Enter 'J5d99bPz' as a code to unlock the Gangster costume.
Biker costume Enter '1gb57M2x' as a code to unlock the Biker costume.
Velvet costume Enter 'F9sT5v88' as a code to unlock the Velvet costume.
Saucer skins Enter 'X91mw7zp' as a code to unlock the Saucer skins.
Mime costume Enter '7qd33J1n' as a code to unlock the Mime costume.
Chef costume Enter '51c24KiW' as a code to unlock the Chef costume.
Kung Fu costume Enter 'Ly11r98H' as a code to unlock the Kung Fu costume.
Sixties costume Enter 'M13Ni95L' as a code to unlock the Sixties costume.

- 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 begin 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.