Crystal Mountain Zone is the fourth level of Sonic Rivals for the PlayStation Portable. Snowy peaks adorned with huge crystals of multicoloured ice, the Zone contains two Acts plus a boss fight at the end. As with most of Sonic Rivals, the Zone is located on Onyx Island: which is Angel Island from the future, warped to Sonic's time by Eggman Nega.
Pondering "Eggman"'s cryptic words about Angel Island after Sky Park Zone, Knuckles runs into Shadow. The black hedgehog boasts that he's not as clueless as Knuckles regarding the scientist's next location, so the two of them race off through Crystal Mountain. When they finally chase down "Eggman", the Doctor reveals to Shadow that he has a card containing Dr. Eggman, before attacking in the Egg Lynx.
Silver, meanwhile, is trying to understand how "Eggman" learned to operate the card-forming camera. Sonic claims he's figured out the scientist's next move - but can Silver keep up with him? At the boss, Sonic demands that "Eggman" hands over Tails card, while Silver finally puts two and two together, figuring out that their enemy must really be Nega.
Freezing crags and bluffs cut through by rocky chasms and chill rivers, Crystal Mountain Zone includes a lot of vertical maneuvering, hopping out of caves on ladders of springs or blasting back down through Holoska-style ice-walls. Frozen grottoes below the surface house spiky sculptures of red and violet ice, while yeti-Badniks patrol between cryogenic geysers in the blizzards outside.
This Zone also features bobsleds, which characters can ride in until a certain point.
|Icy crystals, snow banks, slippery tracks, and freezing waters comprise this winter wonderland. If the blizzards don't slow your racer down, the brittle ice barriers will. Make sure to hop in the bobsled to barrel down the track at death defying speeds.
— Sonic Rivals US manual