Ruin Arm is an action RPG from TOSE and Bandai set in a post-apocalyptic world in the distant future. The hero Arm and his younger sister, both of which can be named by the player, is sent out on a task by their father that eventually turns into a quest to save the kingdom.
The game is an action RPG for up to two players - the second character will be controlled by the CPU if no second player is present. Each character can equip weapons which have a fixed durability, as well as magic that spends MP each time they are used. Dungeons have in-game maps to help players navigate their sometimes maze-like structures.