If I remember correctly, you have to beat the target test with everybody. If that doesn't work, there's a cheat which lets you get a new character always, but I don't remember what that is. Somebody else probably does.
finish adventure, or classic with all the characters
Get all other characters and beat classic/adventure with all of them.
Clear classic, adventure, or target test with the other 24 characters
you have to play as ten characters (2 have to be link and zelda/sheik) in classic or adventure mode, after you do that then he should challenge you.
you have to beat break the targets with all characters, or do classic/adventure mode with all characters, or just play 1000 vs matches. =)
here's how you get roy Play classic or adventure as marth
NO. VERY HARD! you can just do one of the things below . do 1,000 melee matches .complete target test with 24 characters .complete classic or adventure mode with 24 characters.
luigi, just beat adventure mode
beat classic mode with all playable characters, also you might be able to beat adventure mode with all characters to unlock him too.
To unlock game and watch you have to beat classic or adventure with all charaters. Classic is easier.
Beat classic mode with 13 characters then beat marth
Beat Classic or Adventure mode with Mario on any difficulty.