To complete the storyline you have to beat the Elite 4
To really beat the game you have to defeat Red on Mt.Silver
To become a Pokemon master though, you have to catch all 251 Pokemon available in Crystal version
Chat with our AI personalities
defeat Whitney the third gym leader
You go and have a tug
The Karate King! You can get a Tyrongue if you defeat him.
To get a Master Ball in Pokemon Crystal you have to defeat all the gym leaders then talk to professor elm. I advise you to keep the master ball for luigia.
you simply defeat the gym leaders in the johto and kanto regions