Double-panel LCD game (there are two LCD panels on top of each other). The dual panel creates a kind of 3D afffect with lower objects on one panel, and higher ones on the other. Known as Hikyo Amazon in Japan. Neat design, I know of these Double-panel games: Airport Panic, Frankenstein (or Mr. Franken), Hikyo Amazon (or Amazone), Terror House (or Akuryo no Yakata), Zaxxon. All but Zaxxon are solar powered games.
