the player must complete missions, each with objectives that range from collecting coins to attacking enemies. In each mission, the player controls a pre-specified character. There are seven levels with eight missions in each. After completing each mission, the player's performance is given a grade of stars (three, two, or one) or letters (A, B, or C). After all the eight missions in a level are complete, the player must complete a boss mission to advance to the next level. Once the first six levels are complete, and the rank of at least one star has been obtained on every mission, the seventh level is unlocked. Multiplayer modes The game also features a multiplayer mode, in which 8 players race each other using the DS Download Play feature for consoles without a cartridge or a multi-card wireless LAN connection. Available to players are Versus mode (only the Mushroom and Shell cup's levels can be played in a DS Download Play lobby) and the two Battle modes (only three available courses out of six). Players with no cartridges have to play as Shy Guy, a character unavailable for individual use, and are forced to use a standard kart which is colored along with the randomly-selected color of the Shy Guy. Until its discontinuation on May 20, 2014, Mario Kart DS supported online play via the Nintendo Wi-Fi Connection, in which up to 4 players could play together. When playing online, participants could only race against each other; Battle mode was never available when playing via an online connection. These features are not available in the Wii U Virtual Console version because the multiplayer features have not been emulated. Development Nintendo announced on May 11, 2004, that they planned to release a Mario Kart game for the Nintendo DS, releasing some gameplay video footage at the same time. The company offered the game for the public to play for the first time at the 2005 Game Developers Conference, where the game's wireless feature was also showcased. Mario Kart DS was produced by Hideki Konno. The game runs at a consistent 60 frames per second and uses full 3D characters and environments. Mario Kart DS is the first Mario Kart iteration to support online play. Konno remarked that although both Mario Kart DS and the Halo series feature online play, he noted that most of the people who use the feature in Halo