"The player controls a space ship armed with lasers and shields on a mission to destroy the Cosmic Chasm space station from the inside out. Each room of the space station has protector ships that attack the player directly and a center that slowly expands thus forcing the player not to linger in the room for too long after defeating the protector ships. The player must shoot away force fields that protect the exits in order to traverse the corridors that lead to other rooms. Each exit corresponds to a different direction on the map so choosing the shortest route is key. The goal is to fight your way to the stations reactor room, destroy it and make your way out of the station before being engulfed in the station's destruction. Touching the walls of the rooms is just as fatal as touching a protector ship or the expanding center. The screen has a map portion on top so that the player can keep track of which room of the station he is in as well as plan his escape out of the station. The home game is basically the same in game play but has some noticeable differences from the arcade version." Source: Wikipedia, "Cosmic_Chasm," available under the CC-BY-SA License.