Dark forces have set out to destroy the fabric of time, by opening eight space-time continuum portals. Each one is guarded by a great mind, who must have a relevant object returned to them before they will allow you to seal the portals. Doing this requires formulating a spell from the runes the Minds give you.
All of this is played out in a combination of side-view action and icon-based object manipulation. Starting in your living room as you search for a weapon and its bullets, you move along a network of levels and ladders, avoiding or shooting the many foes you encounter. Pressing down and fire together brings up a menu allowing you to pick up items, swap them with Guardians, and cast spells (with the chance to test them first).