ANYTHING that is UNNECESSARY, uneeded or extraneous. Used in a negative way to describe an exaggeration, amplification, boasting, something that is avoidable, unrequired or useless.
"Dude, you're extras! Sit the fuck down and shut up!"
"Man, that party was extras! It was a cock-fest! Told you we should have gone to the club instead."
"This game is extras! You can't even get past the 1st boss without getting owned."