if you eat a flower, you can shoot fireballs out of your hands
if you wear a racoon costume you can fly
you can destroy tanks with pistols (Metal Slug series)
all upgrades look the same, they just fire different things (see above)
if you see a blinking red light, you're fucked (StarCraft)
MY LIFE FOR AUIR
you can miss with a gun point blank (KOTOR)
apparently, if theres zombies running around, people will just leave weapons lying around, or on the walls, or theres a magic box that will give you a random weapon (Nazi Zombies and L4D)
never,EVER, trust a man in a business suit (Half Life series)
mounted guns have unlimited ammo, but their unmounted counterparts don't (CoD4 and Halo 3)
you can kill someone by shooting them in the foot (AWP in CS:S)