Course No.17 is the first secret course of Sherbet Land in Wario Land: Super Mario Land 3. It is accessed after finding the secret exit in Course No.15. The level features Pikkarikun that chase and attempt to attack Wario for most of the level.
During the first part of the level, Wario is pursued by a Pikkarikun that occasionally shoots bolts of lightning down below it as he traverses a stretch of slippery ice platforms with Harisu and many coins. The Pikkarikun stops chasing Wario once he reaches the first door, which leads to a vertical room with a ladder leading up. If Wario climbs it, he passes by four alcoves, each occupied by a Gaugau guarding a block; the lowest and highest ones contain hearts, the second from the bottom contains a single coin, and the third contains a Bull Pot. Once Wario reaches the top of the ladder, he can enter a room filled with blocks containing more of the same collectibles from the previous room.
Past the first door in the main area, Wario must jump along a series of ice pillars while avoiding Watches. He will then come across another door, which leads to another vertical room, this time inhabited by Harisu. After Wario climbs a series of ladders to reach the top, he finds a checkpoint; Wario can then simply follow the line of coins by the right wall and drop back down to the door.
Just past the halfway point, another Pikkarikun gives chase as Wario walks down a straight, slippery path, which is blocked by several breakable blocks. Two Harisu are also found between some of the blocks. Wario can use the ice platforms above him to shield himself from the Pikkarikun's lightning. Eventually, Wario must drop down to a low platform while avoiding the small gap next to it, then jump up to a door to the next area while avoiding another gap on the right. The next area is a flooded vertical room filled with mines and a single Pinwheel, and at the bottom of the water is the door, which takes Wario to a small pond inhabited by a Goboten. After jumping out of the water, Wario finds the goal door.
The key is found in the middle block in the room at the top of the long ladder, while the treasure room door is found at the top of the room through the third door from the main area, just after the second Pikkarikun. In the latter room, Wario must ride a Floater up to the door over a bottomless pit, while collecting a path of coins along the way. The treasure is a bell worth 5,000 coins.