Valis III continues the story of Yuko, the chosen wielder of the Valis sword, as she battles a new threat to the worlds she protects. Players fight through side-scrolling stages using sword strikes and magic against a variety of enemies and bosses.

The game builds on its predecessors by letting players switch between multiple heroines with different abilities during stages, while retaining the series' anime-inspired presentation and cutscenes. It stands as a key chapter in the classic Valis action-platformer series.