Hello, you become the relics, when you finished a level and than return to the same level! Now you must cross the yellow clock! Then a time run start, You must finished the level at a very fast time, then you get get a blue, silver or gold relice!
P.S. Itīs better when you at first killed the last boss (N.Cortex in the last warp room), than you become a feature (now you can run faster while holding R2)
m.f.G. Daniel