Pokemon Ruby is the third entry to the Pokemon game series and features the region of Hoenn. The game features Generation III Pokemon and features a new batch of 150 Pokemon to meet and capture. Pokemon Ruby also introduced the double battle game mechanic that allows trainers to fight a 2 on 2 Pokemon match. The game features the story between two rival gang Team Aqua and Team Magma. Pokemon Ruby is focused on Team Magma and the legendary fire type Pokemon Groudon. On top of all these improvements, the game also introduced the mini game Pokemon Contest and the sandbox Hideout system. Other than these, gameplay is mostly unchanged from the previous games, and still features a genuine Pokemon adventure experience. Have fun!