Pokemon - Gold Version (USA, Europe) ROM

Pokemon gold to me is one of the best pokemon game out and it is so cool that u can get it and play on your phone awesome.

This is one the first two games of generation 2. Pokemon Gold was released along with Pokemon Silver, just like the first generation (Red and Blue) some Pokemons can only be caught in either Gold or Silver, but not both. Pokemon Gold/Silver introduce many upgrades to the Pokemon universe, along with a load of new Pokemons.
The first thing you'll notice is that you're not in Kanto anymore, you've got an entirely new region to explore, Johto. And you can choose from new starter Pokemons. But one of the biggest change is that, the game keeps track of the real-world time, and depending on the time of the day, or day of the week, various events will happen, along with a full day/night cycle. Some Pokemons only appear at night, or only on friday, etc..
The Gyms are also completely different from those in Kanto. And once you've beaten the best of Johto, you can revisit Kanto, and all of it's gyms !
If you've played any the 3 first gen Pokemon games, you really need to play either Gold, Silver, or Crystal ! You'll love it !

 
Pokémon Gold Version and Pokémon Silver Version were the first main series of Generation II for Game Boy Color. They were released in Japan on November 21, 1999, in North America on October 15, 2000, and in Europe on April 6, 2001. Like their predecessor, they are paired versions, with few differences aside from available Pokémon. As Pokémon had become an international phenomenon already with the release of Pokémon Red and Blue Versions and Pokémon Yellow: Special Pikachu Edition in North America and other regions, the localized versions of these games were greatly expected. Much like Red and Green (Red and Blue overseas), Gold and Silver were followed shortly by a third version with minor changes, Pokémon Crystal Version, as well as remakes two generations later in the form of Pokémon HeartGold and SoulSilver Versions for the Nintendo DS. Unlike earlier games, Gold and Silver take place in the Johto region, west of the region that the original games take place in, Kanto. However, Kanto can be traveled to later in the games.