To unlock Tremmel King get all 3 shortcut medals in all of the 8 levels. To unlock Roscoe get 20 Hex Bux in all 8 levels. To unlock Tek - 9 beat the game with any character. To unlock Sydner beat all the levels in the time challenge. To unlock Hex you must beat the game with all 3 original characters (Chops, Zero - G, and Sid). To unlock Gex you must get all the status decals.