It features several Thwomps that try to block drivers from getting to further areas. Near the beginning of the course, there is an imprisoned Thwomp tinted green with yellow teeth due to the lighting, who will shake and laugh if the player goes near it. The laugh can also be heard by the normal Thwomps throughout the course. In further corridors there are pictures of Bowser and large stone statues that shoot flames from their mouths, but they are harmless. At the end of the track racers will race on the roof of the castle. On the last lap, or when the player gets too close to the Bowser statue at the start of the track, Bowser's famed laugh plays. Thwomps are the main obstacle in this course. Most of them will move around the room and try to crush the racers and some slide across the room. The Thwomps' laugh in the N64 version is the same as Wario's, only pitched down. Because Wario's voice changed for the international release, the Thwomps' voices changed with it.
In Mario Kart Wii, the course's layout did not change much, but the sliding thwomps are now angry and there are lava geysers.