Ruin: Kami no Isan is an action RPG. The player navigates Jan through top-down towns and hostile areas; the "world map" is not free-roaming, allowing only linear advancement from location to location. Hostile areas are populated by enemies who are visibly walking on screen. Unlike most Japanese RPGs, there are no separate "battle screens" in the game; the monsters are fought on the same spot they are encountered on, like in action games. However, unlike most action RPGs, there is a party in Ruin. The player controls only Jan, while the other party members act according to AI routines: attacking, casting offensive and healing spells, etc. The rest of the gameplay is traditional Japanese RPG style: acquiring better weapons and armor, automatic leveling up, linear story development, etc.