The name Einhänder is German and denotes a type of sword that is wielded with one hand, here used to refer to the single manipulator arm possessed by the player's spacecraft.

[1] The game is based on the story of the Greek's mythology of Selene and Endymion and set in a fictional future during a war between the Earth and the Moon.

[5] The Japanese version also features a difficulty setting called "Free", which grants unlimited continues but disables the score.

[1] The player's fighter can move at different speeds and is equipped with a default machine gun as well as a manipulator arm, which is used to collect gunpods left by destroyed enemies.

Gunpods have varying amounts of power, ammunition and range, and include cannons, guided missile launchers, aircraft-sized lightsabers and other types of weapons.

However, if the multiplier reaches a certain amount it will begin to flash, awarding large point bonuses for any cores destroyed during this short period of time.

Selene's tactics consists of sending one-man fighter spacecraft called "Einhänder" on kamikaze missions to cause as much damage as possible on the planet before being destroyed.

After surviving the intense barrage of artillery fire of the test, the pilot wonders why they must be terminated by their allies and questions their military leaders' rationale for the war.

[1][7] The game's narrative then skips to one month later when the pilot re-emerges in space flying an armed Einhänder spacecraft.

An epilogue shows the actions of the lone Einhänder pilot ended the war by destroying the armies of both sides — leading to an eventual peace.

The developers used German terms extensively for naming things in the game, in addition to a number of references from Greek mythology and the Bible.

[1] According to the gaming website IGN, a lot of the effects Square learned from creating Final Fantasy VII were also put in use in Einhänder.

[18] In a similar vein as with Final Fantasy and The World Ends with You in previous Kingdom Hearts games, Einhänder is represented in Kingdom Hearts III in the form of the Endymion being a Gummi Ship and Schwarzgeist being a secret boss in the Gummi Ship portions of the game along with a remix of the latter's theme.

AllGame lauded the game's intense action and diversity of spacecraft, the gun pod system and the fact that bosses are composed of different destructible parts.

[20] GamePro noted that while the gameplay scheme is common to other shoot 'em ups, the title's "thumb-busting" action and variety of weaponry made for an enjoyable experience.

[5][26] Concerning the graphics, GameSpot, AllGame and Official U.S. PlayStation Magazine appreciated the level of details and effects used in the different stages, as well as the large size of the bosses.