In the far future, humanity is in search of a new source of energy. They find it on the planet Tetamus II but they must protect the planet from a race of aliens until the energy can be harvested. The player does this by commanding the starship VIXIV through various missions as assigned by the "Training Academy Coach".
After the success of the Starglider 2 game for the Amiga computer, the game's developers wanted to experiment with making a Gameboy game that had 3D visuals. Partway through the game's development, Nintendo stepped in and made the game a first-party game. Even though an international released was planned under the name Lunar Chase, the release was cancelled at the last minute by Nintendo of America because they thought the game was too advanced for a console they were aiming at children. However, the game would get a sequel for DSiWare in 2010 called X-Scape that did release globally. In a 2020 data leak, a fully completed translation of Lunar Chase was dumped online on the same day a mostly complete (and still well-made) fan translation was also released. In addition, Argonaut would later go on to create another game that would begin an iconic series, Star Fox.
Tropes found across this game and its sequel:
- A Long Time Ago, in a Galaxy Far, Far Away...: The game takes place on and around Tetamus II, a planet located in a distant galaxy.
- Brainwashed and Crazy: The Commander ends up becoming this trope in X-Scape.
- Easter Egg: Totaka's Song can be heard in Mission 4 if the player waits 40 seconds when they see the fake scientist. The sequel also has the same easter egg found in much of the same way.
- Excuse Plot: Humans find a new energy source on a distant planet. It's up to you to defend it from aliens.
- Fun with Palindromes: The player's ship is called the VIXIV.
- Human Popsicle: The player character spends the twenty years between X and X-Scape in a state of cold sleep.
- No Name Given: The Training Academy Coach seen in the game is known simply by just that.
- One-Letter Title: The first game's name is simply just "X".
- Previously on…: X-Scape has cutscenes that explain the plot of X due to the former's restriction to only Japan.
- Remember the New Guy?: The VIXIV tank has an AI named VIX in X-Scape. One might wonder why you never heard VIX's voice in the previous game.
- Sudden Sequel Heel Syndrome: The Commander appears to go through this in X-Scape. Turns out, he’s been brainwashed by the aliens, and saves the player in the ending.
- 20 Minutes into the Future: The games are set in the year 8191.
