Hint: Text for Axe Easter Eggs
On the Fremont Street level there is a bottle of Axe on a ledge.
Shoot the bottle and the roof on Fremont Street changes to an
animation of a girl in a bikini with some Axe materials in neon. A
movie opens up showing some outtakes and pretty funny Rainbow
situations/early animations.
Hint - Unlocking Weapons (Campaign)
After destroying the opposition in single player campaign, dont
forget to pick-up each new weapon you come across. While you dont
have to keep a weapon and finish a map to unlock it in your
customization menu, you do need to hold onto it briefly or your
profile will not save it.
Another advantage is once you "claim" the weapon, you can die or
restart the mission entirely and use it in the stage you got it
from. This way, all the enemies you drop pretty much restock that
weapons ammo and you literally will be carrying a portable ammo
dump throughout that stage.
Note: you need to reload your profiles last checkpoint each time
you boot the game to get your gear back. If you choose to load a
stage without loading your last checkpoint, your previously earned
weapons will be lost.