Here's a very interesting game that applies some pretty unique UI
concepts to support a concept entitled "flow theory."
Flow theory [is] a psychological concept first developed by Claremont
Graduate University's Mihaly Csikszentmihalyi ... it mostly boils down
to impulsive, easy-to-understand gameplay that eliminates disruptions.
Nothing comes between the gamer and the experience -- no menus, no
tutorials, no prompts or instructions; most of all, no dying.