Pokemon Crystal is a great sequel to the original Pokemon games and introduces a lot of new features.
Pokemon Crystal has 251 Pokemon to collect which is an upgrade from the 151 collectible Pokemon from the 1st generation of games. You are once again a young trainer aiming to conquer the Pokemon league. This time roaming the land of Johto and conquering whole new Pokemon as well as old. You'll be able to find these Pokemon in various places from tall grass to caves. Like in the previous titles, you'll also be able to collect extremely rare legendary Pokemon. Some Pokemon will not be available at all which means that if you want to collect them all, you have to trade with the 1st generation of games.
When you add in the fact that you have to hatch eggs as well, than completing the Pokedex becomes that much longer to complete. The adventure you go on is enough to distract you so that it doesn't seem as long as it actually is. The completion of the Pokedex becomes harder because of the need to trade with both generations of Pokemon.
This time around, although you have the same goal, you're a different person in a new land. You start out in New Bark Town with either Cyndaquil, Chikorita or Totodile to defeat the Elite Four at the Pokemon League. This time around you also need to collect gym badges, but this time 16 of them total in Johto and Kanto. Along the way, you'll face trainers, towns in crisis and side adventures that'll keep you interested.
The battling aspect of Pokemon is still turn-based and strategic. Your and your opponent's Pokemon take turns hitting each other while Pokemon types affect how much or little damage they do. You can still only hold six Pokemon at a time while being able to hold up to 250 Pokemon in storage. Pokemon will still gain levels, gain higher status and evolve into their mature forms if they have one.
The adding of steel and dark types help make battle a bit funner as well as Pokemon. On top of that, Pokemon can now carry items into battle. Berries being one of the holdable and new items. Items that help Pokemon evolve are still here and there are some new ones as well. You wil carry all these items in your backpack, with machines that let you learn moves manually and a PokeGear device that lets you look at the world map, radio station and a cellphone to help you keep in touch with trainers you have battled.
The difference that Crystal has aren't as noticeable as the differences were in Pokemon Yellow. One that you might have noticed is the fact that you can pick a female character in the beginning or maybe you noticed how the Pokemon tend to show off or something like it before the battle begins. There are other things like the location of Pokemon were switched around, the Suicune side-plot and an easier way to get Celebi.
The day and night feature is still active in Pokemon Crystal. This of course affecting when certain Pokemon come out into the wild and when certain events happen. The Pokedex lets you sort all the Pokemon by their type or number which helps organize things a bit. The multiplayer on this game is just as great as the one from the 1st generation, but doesn't change in any way so it isn't really that much to talk about.
Overall this game is a great improvement over Gold and Silver. Although none of the 2nd generation of games improve radically on the previous generation, they certainly add onto the already great features in the previous generation while adding a few things of their own here and there like the time element and breeding. This game is just as special as the first ones and will certainly be enjoyable to any gamer whether casual or hardcore.