The bright card is your ticket into the secret casio. To get it you must have gotten to bean valley.Then you go back and find knife guy. He is located right before the first save point and he will say he is sorry for hurting you.
Then he will ask you to play a game. He juggels the balls and asks you what hand the yellow ball is in. Guess it right 12 times in a row and he will give you the bright card.
The Casio:
Grate guys casio is an optional area that can be accessed by bean valley if you have the bright card. Get to the part in bean valley where the are 5 warp pipes. Wait for the shyster to water the top-left pirana plant. Then get into a fight with it.After you kill it go down the pipe. Stand on top of the golden chomp's block and jump.It should reveal a hidden block. Jump on the block and follow the path out of the world map.Grate Guy's Casio should be on the map.
