Pokemon Gold/Silver
The whole New Journey is here!

Scores of New Pokemon:
In addition to the 151 Pokemon from Red/Blue/Yellow, there are 99 new Pokemon in Gold and Silver for a total of 250. Six of the new Pokemon are exclusive to each version (as are 4 old Pokemon), for a total of 93 new Pokemon in each version.
New Moves For All Pokemon:
Some of the most exciting Pokemon in Gold and Silver aren't new at all! Virtually all of the Pokemon that were introduced in Red/Blue/Yellow have at least one new move, and most learn their best moves many levels earlier than they did before. These changes are almost all for the better, so in most cases you're better off catching new versions of your Pokemon than importing them from your Red/Blue/Yellow game.
Two New Pokemon Types:
There are two new types in Pokemon GS: Steel and Dark. In R/B/Y, Psychic was an excessively powerful type, since it was strong against common Fighting and Poison-type but was really weak only to seldom seen Bug-type attacks. But now Dark has balanced out Psychic: It's both strong against it and resistant to its effect and even many non-dark pokemon have dark attacks. Dark, in turn, is vulnerable to Fighting and Bug. This gives fighting-type a double boost, sicnce Dark keeps it main enemy (Psychic-type) in check, and is a new type that it's very effective against.
Steel has a much smaller effect on the game, since there are few steel Pokemon and Steel attacks. But it does provide some balance to Ice type (which are vulnerable to steel, as are rock pokemon) and it also makes fighting, fire, and ground Pokemon better, since they are the only types that can effectively penetrate Steels' defense.
The New Pack and PokeGear:
The new multi-compartment Pack in GS seperates your items by compartments: Items, TM's/HM's, Balls, and Key Items. This makes it possible to stay organized and eliminates the need to constantly reorganize your inventory with the Pokemon Center PC's. A very handly item!
Whiel the Pack is an upgrade, the PokeGear is all new. At the beginning of the game, it can be used only as a watch and phone, but as you get new expansion cards, you can add a Town map and Radio Features. When you defeat certain trainers, you can trade phone numbers. They'll call you when they want to challenge you again, or tell you when and where you can catch rare Pokemon! And if you get stuck, you can always call major game characters like Professor Elm or Bill for advice.
The Internal Clock:
The biggest change in the world of GS is the addition of Morning and Night, and the days of the week. The game does not keep track of any other date information so there are no events that happens only in certain months for example.
Day Cycle:
Virtually all shops and characters can be visited at anytime of day or night. The main impact of the day cycle is in the Pokemon you encounter. You'll find different Pokemon in the same area at different time of the day. This is usually only true in outside areas, but there are certain caves, dungeons and towers where this also occurs.
The Week Cycle:
Some events happen only on certain days of the week. For Example, there is a shop that is only open on weekends; a bug catching contest that is held only on Tuesday, Thursdays and Saturdays; and a Pokemon that only comes out on Fridays!
New Methods of Evolution:
This is another massive change. In Pokemon R/B/Y, you could evolve Pokemon in one of 3 ways. By leaving them up by trading them or by using Element stones. Now there are 3 new ways: "Taming" them, trading them while they hold certain items, and breeding them.
One other twist is multi-path evolutions. THis actually isn't new, since Eevee could evolve three different ways in R/B/Y, but it has been added to many older Pokemon who used to only be able to evolve one way. FOr example, Oddish still evolves into Gloom, which can evolve into a Vilepulme with the Leaf stone. But NOW, you can also use a Sun Stone on Gloom and get a Bellossom instead!
The New Special Defense Stat:
In R/B/Y, there was a stat called "Special" that determined both the damage of a Pokemon's Special-ty0e attacks and its defense against such attacks. That stats has now been broken up into two stats: Special Attack and Special Defense. This has had a big effect on the utility of some of the older Pokemon. For E.G., Hitmonlee now has a very high Special defense and a very low Special Attack, instead of simly average scores in both. Thsi is great news for Hitmonlee, since it has no special attacks, but can now better defend itself against its opponent's Special Attacks.
Most Pokemon Have a Gender:
Just as there were male and female Nidoran in R/B/Y, now there are Male and Female versions of (almost) every Pokemon. You'll find that most of the Pokemon in your game pack are one of the particular gender, so it's easiest to trade with friends to get the opposite gender pairs that are useful for Pokemon breeding. By the way, male Pokemon tend to have a Higher Attack, while females have Higher Defense.
Pokemon Can Equip Items:
In Gold and Silver, each Pokemon can hold one item. While they can be made to hold anything, there are two types of items that will actually help them out:
Berries:
There are a ton of different berries in GS. The basic Berry automatically heals 10 HP when they Pokemon that holds it is wounded (and falls into the yellow zone). Other Berries with activate when the Pokemon is holding them is Confused, Paralyze etc. Using a berry does not cost that Pokemon a turn. You can also use Berries outside of battle, just like potions or other items, barries can't be bought, but you can find'em in trees once per day, or in the possession of certain wild Pokemon.
Hold Items:
These are items that have an effect on the Pokemon that holds it, but are not used up. For E.G., leftovers refils a little bit of HP every turn to the Pokemon that holds it. Other items like Charcoal strengthen the attack power of all tchniques of a certain type.
New "Mystery Gift":
If you're playing on a Game Boy Color, you can use this new feature to get up to five free, potentially valuable items a day. To activate this feature:
1. Play until you get to Goldenrod City, speak to the girl in the 5th floor of the Goldenrod Department Store and save your game.
2. Find a friend who has done the same.
3. Place the infrared sensors of your Game Boy Colors within a few inches of each other and choose the Mystery Gift option from the initial menu that appears on power up.
4. You'll each receive an item randomly selected from the Mystery Gift List! Hope it's good! Good Luck! Anyways, you can do this with the same friend everday (but only once per day), or with different friends up to 5 times a day. You can also do it with a Pokemon Pikachu 2 GS, and as often as you like. But instead of being random, the item is based on the wattage of the Pokemon Pikachu 2 GS.
Many of the items you'll get this way are "decorations" that you can use to customize your character's room. But you can also get valuable items like Elemental Stones this way =)
And So Sooooo Much More . . .
Where to begin? There are two new HM's - Waterfall and Whirlpool, dozens of new attacks, useful out-of-battle moves like Rock Smash and Headbutt, all new TM's, cool items, alternative color Pokemon and much more!! Experiment, discuss with your friends, and ENJOY Pokemon G/S!
More info soon!