There is no game called Super Mario 63. There is one called Super Mario 64. On the final level of it you have to fight and defeat Bowser.
defeating bowser
You need to go search ,,super Mario 63 level designer" to click the differenct super Mario 63 level designer button.
type:mario 63 level desiner
in the last level
Bowser's Third Castle
fess
All you do is type Super Mario 63 (Level editor) (Of course you will loose everything in the one that you have and you will have the level editor though but loose all saved files.) There is another way (Go and make your level you can always come back and play on the previous Super Mario 63 that has no level editor but still have Saved Files
get 54 shine sprites and beat the final boss
the catle how do you get a star and sunshine
Press P then press exit then press quit game or exit level
yes it is impossible to play as shadow in Super Mario 63
Because they tricked you,but there MUST be a pipe in the room that will take you to that level.
Mario 63 Shine Sprites