items carried by each racer, and a map of the course. The bottom screen can be toggled to show either an overview of the entire course, or a bird's-eye view of the player's kart and the immediate vicinity, including nearby racers, course hazards, item boxes, and incoming attacks. Each course features item boxes that the player can drive through to receive a randomly selected item, which the player can use to gain an advantage over other racers. Some items allow the player to attack other racers to slow them down, while other items can be used to speed up the player's own kart to pass other racers more easily. There are two new items: the Bullet Bill, which transforms the player into a Bullet Bill that autopilots the track; and the Blooper, which squirts ink on all racers ahead of the user, blocking their vision. Unlike the other versions of Mario Kart, Mario Kart DS allows players to avoid the Spiny Shell (Blue Shell) without any aid from items. This can be done by releasing the mini-turbo right before the Spiny Shell hits the player. This requires precise timing, and it is one of the most difficult skills to acquire in the game. Furthermore, this trick is mainly only possible in 150cc or Mirror Mode. However, it is also possible in 100cc, but only on tracks such as N64 Frappe Snowland, where the terrain is more slippery. Game modes The game features five single-player game modes: Grand Prix, Time Trial, Versus, Battle, and Mission. The Grand Prix and Versus modes require that the player choose an engine class from among 50 cc, 100 cc, and 150 cc. The classes serve as difficulty levels—the higher the engine class, the faster all karts go. In addition, a Mirror mode can be unlocked, in which karts use 150 cc engines and tracks are horizontally reversed (including signs and lettering present in the original orientation). Grand Prix In Grand Prix mode, the player competes against seven computer-controlled racers in a series of predetermined courses. Unlike previous Mario Kart games, which featured four cups, Mario Kart DS features eight cups: Mushroom, Flower, Star, Special, Shell, Banana, Leaf, and Lightning, with the latter 4 cups consisting entirely of tracks drawn from the previous entries in the Mario Kart series. In addition, half of the nitro cups and retro cups are unlocked through gameplay. Each cup has