Once you unlock a character, they become selectable as opponents in other modes of play, such as Free Play, Ranking Play, and Multiplayer Play.
Petey Piranha - Clear all 5 stages in the Medium Level of Challenge Mode
Waluigi - Beat all challenges in the Basic Level
Wario - Beat all challenges in the Basic Level
Verified by: this cheat is unverified
Submitted by: Super Vegeta
on April 25, 2007