Pokemon LeafGreen is a 2004 remake of the original Pokemon Green, bringing the originals into the third generation of games. This update included updated graphics, quality of life improvements, and came bundled with wireless adapters which allowed the wireless trading and battling of Pokemon. LeafGreen was released shortly after Ruby and Sapphire, and the graphics are in the same style. This was my second Pokemon game ever after Pearl, and though I never got far in it, it still holds a special place in my heart despite how mediocre I might now feel it is in the face of other remakes.
Pokemon Leafgreen and FireRed are set in the Kanto region, with the Sevii Islands being unlockable after the Elite Four are beaten. The game primarily features the original 151 Pokemon, though the Sevii Islands do feature many Pokemon that were exclusive to the Johto region.
You play as a young trainer that has just received their first Pokemon, either the fire-type Charmander, water-type Squirtle, or grass-type Bulbasaur. As with other Pokemon games, your intial goal is just to beat the Pokemon League and become champion, but this is hampered by a group known as Team Rocket. Team Rocket wants to use Pokemon for profit and other nefarious purposes, and so your goal becomes stopping them while still continuing to complete your gym journey.