All Pokemon games follow the same plot line, save the world from some mad people.
The main difference (which are the same as in all games) are new pokemons, new legendaries, new map and new items.
I believe Pokemon world online is different from Pokemon crater.
It is the same as any other games, but you can't trade with other pokemon games. You can only trade your pokemon from the different generation games, you can't give your white version pokemon to the earlier generations.
No, until you get the national pokedex. But even then you can't get all of them yet. You may have to buy some of the other games. You'll have to migrate and go to different places while you have different games in your D.S. to get different pokemon. That's about all. Later!
Pokemon can not transfer backwards. You can get Pokemon from other games to Unova, but the opposite is impossible.
Luxio evolves into Luxray at level 30 in Pokemon Platinum. To date Luxio has not had different evolution conditions in other pokemon games.
Luxio evolves into luxray at level 30 in Pokemon SoulSilver. To date luxio has not had different evolution conditions in other pokemon games.
You can't. Just like other games there can only be 1 profile.
Caterpie can evolve into metapod starting at level 7. The evolution conditions for caterpie are not different in Pokemon Yellow from other pokemon games.
They are fan made games (Hacks) of other Pokemon games.
after you beat the Pokemon league
yes get all the pokemon games and you will see
Start a new game on two games. Then start each game on a different Pokemon. then trade one to the other and restart the game with a different Pokemon and repeat the process.