Yakuman DS is a video game developed and published by Nintendo itself for its DS portable platform, and bases its gameplay around the traditional Chinese puzzle game of Mahjong.
What makes Yakuman that more special is that Nintendo features some of its most famous characters from the Mario franchise, including the popular Italian plumber, his brother, Luigi, as well as other appearances from Princess Peach, Yoshi, Toad or Donkey Kong, not to mention various antagonists like Wario or Waluigi.
The game was released in 2005 for the handheld platform, and was eventually re-released in its native Japan with an online mode, under the name Yakuman DS with Wi-Fi.
The game is an actual sequel to the original Yakuman, which appeared back in 1989 for the first Game Boy handheld.
Yakuman DS has multiple gameplay modes, including a Free one, in which you can choose the CPU opponents to play against, a Challenge mode, in which you win the game by completing certain objectives against a given set of opponents, or a Ranking mode, where you start at rank 20 and must complete matches to reach level 1.
There are two multiplayer modes, a local one, in which up to four players can compete against each other through the Nintendo DS' wireless connection, and an online mode, where you must swap friend codes and use the wireless Internet connection of the DS.
In the last mode, the voice chat option is also available so players can interact more freely using the DS' built-in microphone.
Complete the indicated task to unlock the corresponding character in Free Play, Ranking Play, and Multiplayer Play modes.
Bowser: Complete all six stages in Challenge Mode under the Hard difficulty.
Petey Piranha: Complete all five stages in Challenge mode under the Medium difficulty.
Toadsworth: Complete all eight stages in Challenge mode under the Expert difficulty.
Waluigi: Complete all five stages in Challenge mode under the Basic difficulty.
Wario: Complete all five stages in Challenge mode under the Basic difficulty.