In a departure from other games, instead of controlling Vic Viper, the available ship is called Metalion. Unlike other titles, this game has a heavier focus on story, which is told by cut-scenes. The gameplay is mostly unchanged from the rest of the series, though there are some powerups that temporally gives the ship some enhancements. Also, when the bosses are being defeated, if the Metalion flies where they are, a mini-level can be accessed in order to obtain new permanent upgrades, if the mini levels are successfully cleared.
New weapons:
To get them, the player had to enter into the main bosses ship just after the big explosion when the combat ends. Then a slow alarm sound appears, indicating there's still time. Once the player gets inside the bosses, a short stage has to be completed (the same for every boss). When the nucleus of the boss is destroyed, then the new weapons may be granted:
If the big boss was killed in less than 15 seconds, 2 weapons are granted.
If the big boss was killed in less than 30 seconds, 1 weapon is granted.
If the big boss was killed in more than 30 seconds, no weapon is granted.
On the X68000 version, you get one weapon, no matter how long it takes to kill the boss.
| Stage | Description | Boss(es) |
|---|---|---|
| 1. Giant Statue Planet | Giant rotating guns and living statues block the player's progress. | Riot Warship |
| 2. Jungle Planet | Mysterious plants sense the players and release mechanical spores. | Misuhuitsutsu / PLANT Core (X68000) |
| 3. Ancient Planet | A winding maze filled with deadly traps awaits the players. | Misuhuitsutsu |
| 4. Floating Continent | A stage set on a floating mass of land with enemy guided lasers. In the X68000 version this is changed to an ice planet. | Big Core X10? |
| May-heme Warship | ||
| 5. Solar Area | A stage set on a planet that spews massive hot flames at the players. | May-heme Warship / LASER Core (X68000) |
| 6. Living Planet | A massive living planet regenerating at high speed and constantly changing. The boss to this stage has no "Core" section. | Biological Organism |
| 7. Fortress Planet | A heavily armored planet, plated with special metal. There are several mini-bosses to be faced before reaching the end of this stage. The boss to this stage has no "Core" section. | Abadon |
| 8. - 13. | These stages are the same as the above stages in reverse order. The X68000 port changes stages 10 and 11. | Same as stages one through six |
| 10. Asteroid Field. | An deadly asteroid field filled with high speed obstacles and gun turrets. Only appears in the X68000 version. The music used is the same as the cutscenes. The boss to this stage has no "Core" section. | Big Core Mk.2 |
| 11. M Class Planet | A green planet filled with deadly waterfalls and bares a resemblance to the first level from the original Gradius. Only appears in the X68000 version. The music used is the same as the bonus levels. The boss to this stage has no "Core" section. | Bubble Core |
| 14. Venom's warship | The warship of Dr. Venom. It uses the same tileset as the "cores" of the regular bosses. The boss to this stage has no "Core" section. | Dr. Venom |
This is not the only Gradius II. In 1988, Gofer No Yabou (The Ambitions of Gofer??) was ported to the NES, and dropped the "Gofer No Yabou" title. It is similar to its older brother, but it does have differences.