The game starts in the year 2010 and players must destroy the enemies in the past so that the player can confront the final boss in the year 2137. When the player's ship is destroyed while navigating through the air, his score time is cut in half. The highest possible score in the game is 99,990, which is used as currency in the dungeons and the time travel sequences. A completely non-linear structure allows players to travel back in time nearly at will. The farther away in time that the player wants to travel to, the more "time units" are required to reach the destination, acting like the player's fuel supply. After accomplishing the missions that can be done through the spacecraft, the player must land on the ground and accomplish missions on foot.

While the player is stationed on the ground, this video game functions as a dungeon exploration game with shoot 'em up elements. This game has two endings; a happy ending where the history of the planet has been saved and a sad ending where the revelations of Gordess' resurrection has come true. After achieving a game over, players can press the start button to continue the game (in the year 2010) with all their possessions intact as long as they don't press the reset button or turn off the console.