Nippius is the second level of the episode Gene Machine from Jazz Jackrabbit.
After ruining the Temple of the Turtle and stealing a Turtle Spacecraft, Jazz hops to the next planet- a *freezing* ball of ice infested with penguins and (you guessed it) Snow Turtles! Careful not to slip and slide into danger.
While the design for Nippius isn't very complicated, the path is made harder by the presence of the Snogoons blocking the paths and the many springboards which will often force you back into a previous block of the stage. Right by the checkpoint of the first area you can find a secret passage which will take you to Nippius's secret level.
Right on the beginning of the second area you'll find a high-speed section which a big downwards zigzag course ending on a springboard, which will force you back the entire path if you collide with it.