Go underground with our biggest content pack ever released: 11 new tracks (complete with 9 classic tracks, one new Skill game & one new FMX track), 27 new challenges (from secret locations to surprising mini-games), a new 'Billy Gruff' helmet and skin for TKO-Panda, dozens of new editor objects (including mammoth sized heavy-duty machinery, dynamic lava and a genuinely epic train set), 5 new trophies, and 10 secret audio logs to be found.