You must conquer Team Rocket and drive them out of Johto for good, all while training and battling your way to the league.

The main differences in story that Crystal presents is the way you
obtain Legendaries. Suicune is much more prominent and no longer roams,
being available for capture in the Tin Tower after seeing it in
various locations. It introduces a new character, Eusine, who is racing
against you to capture the North Wind Pokemon.

Despite it being the usual Pokemon formula, and only minorly
different from Gold & Silver, like its big brothers Crystal manages
to keep it engaging without being repetitive, and the storyline is
rarely disrupted by grinding. Though Team Rocket loses their darkness
somewhat from Generation 1 (after all, they did kill a Marowak), and
their actions don't provoke as much emotion in the player, they are
still decent, if petty, villians. When I first played Crystal in my
younger days, there was a definite sense of accomplishment when you
freed Goldenrod from takeover.

The story is a strong point of the game, and while predictable, is
charming and a refreshing change from the storylines of later Pokemon
games, where the evil team seeks a legendary Pokemon to cause great
disaster.Control wise, Crystal is identical to Gold and Silver in every way.
You open the menu with start, assign a key item to Select, and use the
d-pad to move around, select items, pokemon, ect, from a list, A to
confirm and B to cancel. Basic controls, but very easy to get the hang
of. However, because of select and start being at the bottom of the
gameboy, it can be aggravating sometimes, but this is a minor
annoyance, and certainly not one detrimental to gameplay or exclusive
to Crystal.

One big difference Crystal has is the option to choose your gender.
Yes, for the first time in a Pokemon game, you can run around in all
your girly glory. The female avatar is the blue pigtailed heroine Kris
(sometimes called Crystal, Crys or Krys). This was the huge selling
point of Crystal for me - I could be a girl. And while I had no
problems with playing as a male avatar, and I still don't, it was nice
to be given that option, and Kris was an awesome looking character. It
recognized that Pokemon had female fans and thus should have a female
avatar too. Something that Harvest Moon didn't bring till More Friends
of Mineral Town and Another Wonderful Life (I may be wrong there) for
GBA and GCN, and even longer for both avatars to be on one game

I give the story 6/10. More differences from Gold and Silver were needed.