Gex/Nightmare Fuel


 * Rez and his respective stages, which both add a dark atmosphere to the usually cartoony game, and the floors and walls of the levels appear to be made out of metal and  flesh.  The idea of Rez abducting innocent people to be mascots for his network is unnerving, too.
 * The life-loss fanfare from Enter The Gecko might make you jump the first time you hear it, but the game over music is an Up to Eleven horror remix, to really let you know you messed up. Deep Cover Gecko shares a fanfare for losing a life and getting a game over, but fortunately, it's more comical than scary.