The Coreship appears in Gradius: The Interstellar Assault.
100 times larger than the Vic Viper, the Coreship is a massive, mothership-sized version of a Big Core warship. It's first found when the player is captured shortly after the ruins section of Gradius: The Interstellar Assault. Rather that fighting the ship head-on, the player ends up being pulled into its interior. This becomes the second stage of the game.
While the player never fights the Coreship head-on, it does tangle with the Coreship's reactor. The reactor never directly attacks the player, but is able to suck the player forward as varying speeds. There's also a pair of cannons mounted above and below itself (which can be destroyed) which fire three-way shots diagonally. Electrical panels line the ceiling and floor and create impassable walls of electricity when they discharge.
|Game Boy Gradius games|
|Ships||Vic Viper • Coreship|
|Nemesis Stages||Volcano • Cell • Moai • Bone • Fortress|
|Gradius: The Interstellar Assault Stages||Remains • Battleship Interior • Asteroid Belt • Planet Surface • Fortress|
|Nemesis Bosses||Volcano • Super Big Core • Zub Rush • Crawler • Zigzag • Striker • Amb • Reckless • Mother Computer Z|
|Gradius: The Interstellar Assault Bosses||Infected Statue • Core Reactor • Volcano Core • Fortress Gate • Guardian Core • Escape Ship|
|Big Cores||Big Core MK I • Big Core MK-I Rev.2 • Big Core MK II • Big Core MK II Kai • Big Core MK III • Big Core MK IV|
|Big Core variants||Beacon • Blaster Cannon Core • Bubble Core • Circle Core • Coreship • Crater Core • Crystal Core • Dellinger Core • Desert Core • Heaven's Gate • Juggler Core • Laser Core • Lizard Core • Neo Big Core • Perla Meralda • Rexion Core • Rolling Core • Shining Core • Super Big Core • Terra Core • Vanishing Core • Genocide Core • Odin Core|
|Core-style bosses||Abaddon Warship • Covered Core • Covered Core MK II • Dead End • Kraken • Mayhem Warship • Metal Slave • Misfit Warship • Queensrÿche • Riot Warship • Plate Core|
|Pseudo-Cores||Death • Death MK II (DeathDouble) • Death MK III • Beta Core • Nobil • Triple Core • Crash Bam|
|Tetran variants||Tetran (Zylom) • Covered Tetran • Crystal Core D-X02 • Laser Tetran • Tenny Rop|
|Parody Cores||Candy Core • Decoration Core • Decoration Core MK II • Viva Core|