Robotnik Winter is, predictably, cold. Snow blankets the ground to such an extent in fact that snowboarding becomes an extremely quick way of blasting through the level. Snowdrifts occasionally conceal dark pits in the network of caves that course through the frozen ground. Breakable ice walls and powerful updrafts enable Sonic or Tails to proceed back above ground.
The early part of Act 3 requires the player to climb up the slopes of an icy hill, all the while being forced to dodge skating bomb-penguin Badniks descending from the summit. At the top, the player finally finds the source of this stream of robots: Giga Thomas "Pen", a giant, flying penguin head that spits the smaller Badniks at Sonic from the depths of its cavernous maw. Landing 8 hits will cause the boss' thrusters to fail, and he spirals away into the depths of a huge pit.
After the boss, Knuckles shows up again to spring a similar trap as in Great Turquoise Zone, this time, however, he hits Sonic with a snow avalanche.