Abadox

The game has often been noted by critics for its difficulty, with the player being instantly killed by a single enemy projectile.

In the year 5012, the planet Abadox is eaten by a giant alien organism known as Parasitis. Having consumed Abadox, the alien takes the form of the planet and seeks to devour other planets. The galactic military launches an attack but is destroyed by Parasitis who goes on to devour the hospital ship carrying Princess Maria. Second Lieutenant Nazal, the only surviving fighter of the galactic fleet, attempts to enter Parasitis's body and rescue Maria before it is too late.

The gameplay largely follows the conventions of side-scrolling shooters of the time. The player shoots down various enemies, almost all of which look like various internal organs (brains, eyes and even cilia). The player can also pick weapons and power-ups. Power-ups include speed boosters, increased firepower, homing missiles and shields similar to the "Option" featured in Gradius. For weapons, the player starts with the normal single shot, but can upgrade to a 3-way gun, a spread fire gun, a laser and a hoop-like weapon. However, like most shooters, if the player is killed, all of the upgrades will be lost and the player will have to restart from the last checkpoint. In some cases, if the player dies, they may have to navigate through enemy fire with slow speed, which could prove more difficult than ever. Another aspect of Abadox that sets the game off from other shooters is the second, fourth and sixth stages. The play style changes from a side-scrolling perspective to a vertical one, but instead of scrolling upwards like a typical vertical shooter, the stage scrolls downward. The final stage involves an escape sequence where the player must navigate out of the alien's rectal cavity before the alien implodes. This falls in suit with a Konami title, Life Force, to which Abadox bears a striking resemblance.

The music and sound effects for Abadox were produced by Kiyohiro Sada (credited as K. Sada), who composed music for several NES games from Konami, such as Contra, Blades of Steel and Rush'n Attack.