This is a glitch in Crash Twinsanity that provides the player an easier or harder way to retrieve gems, most of which are for N. Sanity Island. For the gem, where the player must run the chickens into nitro crates, Crash can hop on a fence, and onto a tree, and then hop onto the platform where the gem is located.
The blue gem, on the other small nearby island, can be reached by a harder method; by hopping on the rocks next to the palm tree, close to the ending "way-back path", so Crash can hop on the lower rock part, up to the higher part, then hopping on the palm tree, then onto the platform, then backtrack the platforms all the way to the island where the blue gem is located on a platform.
Finally, the clear gem seen in Jungle Bungle can be gotten with the hard method of trying to blow off the spikes of the almost unreachable Tiki. Crash can blow the spikes off of only the last Tiki next to the platform, roll the hay stack onto its tongue, then quickly hop on it and then to the platform before it blows up. Then, the gem will be obtained.
The clear gem in Twinsanity Island can be obtained easily by belly flopping over the force field. For some reason it's the only one that works. The red and green gems can be easily obtained through suicide (red) or a careful jump (green).