Earned by breaking every box in a level or completing secret routes.
There are 5 colored gems (Blue, Red, Green, Yellow, Purple) hidden across specific levels that unlock secret paths in other stages.
Beating the final boss (Cortex) unlocks the ability to sprint, which is essential for obtaining time trial relics in the N. Sane Trilogy version. Secret Locations and Colored Gems Finding these gems is the key to unlocking the full game: