Pokémon Pure Silver
A hack of Pokémon Silver for the GBC
This hack builds off Pokémon Silver, adding the following features:

It is possible to obtain all 251 generation II Pokémon in the game, without trading.
There are substantial in-game events based around all the rare or legendary Pokémon which were missing from Silver.
Shiny Pokémon - though still very rare - are much more common than they were originally.
Update July 9, 2011: Redditors NethChild and zsghyk found that the trading event was broken - it didn't add the evolved Pokémon to your Pokédex. I've uploaded a new patch which should fix the bug. If you apply the patch your copy of the hack rom, or if you replace it with a freshly patched Silver rom, the event will work.
Now, I'd like to state a bit of the philosophy behind the design of this hack. I don't claim that the Pokémon series ended with generation II. Although I missed Diamond and Pearl, I've played through and enjoyed all the other generations. However, I do think that the sheer number of monsters that exists now makes completing your Pokédex alone with a single game intractible. With that said, my goal with this hack was to create the definitive single-player and single-game Pokémon experience: a neat, self-contained quest to catch them all.

The second feature is particularly important to me. The Pokémon series has always had an incredible amount of interesting lore. Based on the backstory, the creatures have fantastic powers: controlling the weather, travelling through time, and even influencing people's thoughts. But Game Freak has done a terrible job of integrating this lore with the gameplay in meaningful ways.

I think an example will explain it best. Generation III introduced Articuno's signature move, Sheer Cold. This move carries an excellent flavor - just imagine the bird radiating cold so intense that nothing can get close to it. But in the game, Sheer Cold was just another Guillotine/Fissure/one-hit KO attack, nearly indistinguishable from moves that other Pokémon learned. In Pure Silver, instead, this bit of lore is expressed in the mechanics of the Articuno event. And believe me, when you venture into the Seafoam Islands cave, you will feel it.

I've implemented and tested all of the events I wanted to include, but this hack is still something of a late beta. I haven't done a full run-through of the game to catch all 251 yet, and I'm looking for testers to try to break it. See below for brief hints about finding and solving the new events.

Send me an email at skishore@mit.edu with comments, suggestions, or bug reports, or go back to my page.

Hints for indivudual Pokémon (highlight to read):

Johto starters: Look for one in Dark Cave. Buy something from an NPC in Goldenrod for the other.
Squirtle: Visit the house at the top of the Cycling Road in Kanto.
Ivysaur: The monster is hiding in a tree on Route 25.
Charizard: Find a character who needs help in Pewter City.
Kabuto, Omanyte: They lived in the distant past, in what are now the Unown Ruins.
Missing Gold wild Pokémon: They're in the tall grass in some of the locations they were in Gold.
Pokémon that evolve by trading: Find the real McG in Blackthorn City.
Articuno: Still at Seafoam Islands. Only one Ice-type Pokémon can learn Waterfall.
Zapdos: Find a way to attract Zapdos' attention at the Power Plant.
Moltres: Why did it return to Cinnabar Volcano? Your Master Balls - you will not need them here.
Mewtwo: Still in Cerulean Cave. One of the easier events.
Mew: Legends say that Mew walks among people in disguise. Look around towns in Johto.
Celebi: Offer a natural gift at the shrine in Ilex Forest.
Good luck!