To unlock goku, beat classic mode with samus on very hard with no continues. Then beat classic mode with the ice climbers on very hard with no continues. And finally, beat adventure mode with link on very hard with no continues. Do not press up+b!!! Doing so will reset the code!!! You can use the grapling hook to get back up but don’t press up+b! Note:goku will replace samus on character select screen, so do not use unless you don’t want samus.