Take the ‘Say Hi To The Internet’ achievement, for example. The achievement description states that this is unlocked by ‘finding the lost Hollywood Star’. When I first set out looking for this achievement I thought I’d be searching for an actual, five-pointed star but when you explore the beaches of the Rook Islands at X = 620.2, Y = 557.1, you’ll find a rather peculiar sight; a head of a person buried in the sands.
It’s actually the head of actor Christopher Mintz-Plasse, who played the character McLovin in Superbad. Simply finding this Star will get you, the achievement and a cool 10 gamerscore.