Gravity falls secrets Wiki
(If you play the gravity falls theme song backwards, you will notice it says "3 letters back" and then the gravity falls game, there is a secret code, which you have to decode, it says "Evr noticed stans tattoo")
Stans tattoo looks like a compass when hes wearing his underwear and shirt.
In the theme song, there is a picture of a guy with goggles, if you ceased to notice, he has been in every episode of gravity falls, as a backround character.
Also in the theme song, for one frame there is a big foot in the backround, which is hard to see, but possible to notice.
Stan has a secret hide-out behind a soda machine, which you could see in the first episode, he went into it. -p-e~a~c~e~45