Recurring gameplay elements
There are several gameplay elements that are common to almost all the Gradius games. These include, but are not limited to:
One of the defining characteristics of the Gradius series is the use of a "power meter". The power meter is powered by a power-up item, whose purpose, when collected, is to move a highlight to the next power-up on the power meter. When a power-up that the player wants becomes highlighted, they may activate it, causing the highlight to move back to the beginning again.
Thus, when the player collects a power-up item for the first time, the first power-up (usually a speed increase) becomes highlighted.
The player may now activate this power-up to increase their speed, in which case the meter will revert to its original unhighlighted state. If, however, the player does not activate the power-up, and collects another power-up item, the highlight moves to the next item; in the original game this was a missile.
The player may now activate this to receive a missile weapon, again causing the bar to revert to its unhighlighted state, or choose to hold out for the next item, a double gun. Traditionally, the power-ups with greater effects are placed toward the end of the bar, so that the player must do more work to obtain them, although in some titles like Gradius III a harmful power-up exists at the end which will restore the default (weak) weapon configuration.
Other games using a similar power-up method include Contra Force by Konami, Slap Fight by Toaplan, and Rare's Cobra Triangle.
Weapon edit, first introduced in Gradius III, allows players to construct a custom weapon route from the basic categories, such as missile and laser, and replace these accordingly with a variation of a weapon of their choice.
The concept of the "Core" is a central part of Gradius. Cores are usually blue, glowing masses of energy hidden within large warships and protected by a series of barriers. All cores must be targeted in order to defeat a warship, which normally comprises several phases and often uses the terrain to its advantage. Additionally, the announcer will normally urge the player to "Destroy the core!" or "Shoot the core!" prior to an encounter. For other types of bosses, like large beasts, the announcer may command the player to "Destroy the eye!" or "Destroy the mouth!", depending on the boss.
For reasons unknown, the famous Moai statues appear as enemies in several Gradius games. They are mounted on either side of the ground (which are flat free-floating platforms) and fire a series of colorful rings at the Vic Viper. The weak point is at the mouth, when open. Because they face at an angle or lie flat on the ground, the up-facing Moai are best destroyed with missiles. Since then they have become so intertwined with the series it is not uncommon for them to cameo in other Konami games. There have even been four games where the Moai have even been a playable character. The first being in an action platform game with Konami characters called Konami Wai Wai World and a platform/puzzle named Moai-kun, both for the Famicom. After turning up in the PlayStation battle game Poy Poy, they later appeared in a racing game titled Konami Krazy Racers for the Game Boy Advance and in the fighting game DreamMix TV World Fighters for the Nintendo GameCube and PlayStation 2. In the PS2 game Castlevania: Curse of Darkness, a player can collect a Moai item behind the castle, provided they have a Castlevania: Lament of Innocence save on the memory card. They make brief showings in the video game Tyrian by Epic Games. And a Moai mask also can be found on Hideo Kojima's Snatcher.
Easy final bosses
Unlike other scrolling shooters, as well as many video games in general, the final boss of most Gradius games (including its spin-offs) is surprisingly easy given the difficulty of the final stage and previous bosses (although one could say that the defenses immediately before the boss are so strong precisely because the boss is so weak--it desperately needs the protection). The final boss is usually brain-like in appearance and occasionally taunts the player in a brief "this is only the beginning"-type speech prior to destruction. They can usually be vanquished by shooting once at a number of cores without any retaliation from the boss.
After the credits roll at the end of the game, the game restarts at the first stage with the Vic Viper stripped of all power-ups. Each loop becomes progressively harder as enemies gain greater speed and projectile capabilities. This cycle normally continues up to the limit specified within the settings for arcade based titles and indefinitely for certain console versions until the player exhausts all reserve ships and chooses not to continue.
First introduced in Gradius II, and in some instances referred to as 'Boss on Parade', the Boss Rush is a sequence of boss encounters where the player must fend off four or more Core Warships and in some cases biological entities, some of which are recreations of preceding games.
The Option Hunter (also called "Option Eater" and "Option Thief") appears from the left side of the screen at regular intervals if the player carries four Options. Before launching from the left, it briefly makes its presence known with a loud siren and temporarily mimics the player movement to better its chances of capturing Options. Unless the player takes evasive action, any or all Options may be removed. The Option Hunter has never appeared in any of the Salamander Series.
- Gradius (1985)
Originally released as an arcade game, and later ported to other platforms. It is known to exist on the following platforms: NES/Famicom, MSX, TurboGrafx-16/PC Engine, Sega Saturn, PlayStation, certain mobile phones, and computer (Saturn, Playstation and computer version are all packaged with Gradius 2 as Gradius Deluxe Pack), as well as a re-release of the NES version for Wii and 3DS Virtual Console). In some territories, Gradius was released under the name Nemesis.
- Gradius II (1988)
Bearing no relation to the MSX game titled Gradius 2, Gradius II is the sequel to Gradius in terms of chronology. The game was never released in North America in any form, until recently with its inclusion in the PlayStation Portable title Gradius Collection.
- Gradius III (1989)
This title introduced the "edit mode" method of selecting weapons, which allowed players to create their own weapon array by choosing power-ups from a limited pool of available weapon types (some weapons in the preset weapon types are not selectable in Edit Mode, although it includes weapons not in any presets). The SNES/SFC version is not a very accurate port; levels, enemies, and weapons were altered. For example, two entire stages were cut from the Super NES version: a 3D stage which involved avoiding hitting cave walls from a unique first-person perspective behind the Vic Viper, and a crystal stage in which the Vic Viper was challenged by crystal blocks blocking off areas like a maze. Also, the order of stages was changed. The final stage in the SNES version was based on an early stage in the arcade version. The original arcade version's ending had the main boss in a mechanical setting, then going through a speed-up zone to escape the enemy base, where the SNES version had the player simply avoiding the final enemy's laughably simple and slow-moving attack patterns with no challenge afterward. However, the SNES version introduced the Rotate and Formation Option types, both of which were reused in Gradius V. The difficulty and major boss tactics were toned down to make it easier. The original arcade version is available for PlayStation 2 bundled with Gradius IV (Gradius III and IV), although the port has some slight differences from the original.
- Gradius IV (1999)
Released in Japanese arcades as Gradius IV Fukkatsu (Fukkatsu being Japanese for "revival", since it was the first arcade Gradius game in 10 years, following 1989's Gradius III). IV lacked the Weapon Edit function of its predecessor, but it had a bigger array of weaponry than the original Gradius games. Weapons exclusive to this game included the Vertical Mine missile (which detonates in a vertical line shortly after deployment) and the Armor Piercing laser (a shorter, more powerful laser). Released on the PS2 as a compilation pack together with the arcade version of Gradius III ("Gradius III & IV").
- Gradius V (2004)
Gradius V was released in September 2004 for the PlayStation 2. Graphics are rendered in full 3D, although gameplay is still mostly 2D; some areas change the position and perspective of the camera to emphasize the 3D environment. Treasure Co. Ltd (developers of the classic games Gunstar Heroes, Guardian Heroes, Radiant Silvergun and Ikaruga, among others) were primarily responsible for Gradius V development. In Japanese first press limited edition, the game included a book indicating inner design, the background, and the roadmap of Vic Viper series (i.e. Vic Viper is the name of a ship series, rather than a single ship), and pre-ordered North American copies included a DVD detailing the history of the series (including Scramble) and replays of Gradius V.
- Gradius Gaiden (1997)
The first Gradius produced exclusively for a home console. This is also the only Gradius game (other than GOFER no Yabou Episode II on the MSX) where players can select which ship they wish to use. Gradius Gaiden includes the Lord British Space Destroyer from Salamander and two (relative) newcomers -- the Jade Knight and the Falchion β (a variation of the ship from the Famicom Disk System game Falsion). It was originally released for the PlayStation console and ported in 2006 as part of Gradius Portable for the PlayStation Portable.
- Solar Assault (1997)
Solar Assault is an arcade 3D rail shooter in the lines of Star Fox or Panzer Dragoon, with Gradius's settings. As usual, Vic Viper makes an appearance here. This game was very obscure and was never ported to any console system.
- Gradius Galaxies (2001)
The first Gradius to be created by a development team other than Konami's own internal teams (by Mobile 21 Studios, to be exact). It exists for the Game Boy Advance. It is known as Gradius Advance in Europe, and as Gradius Generation in Japan. The Japanese version, being the last to be released, has a number of exclusive challenge modes added that the other versions did not, and includes an additional invisible 5000 point bonus in one of the levels.
- Gradius NEO (2004)
A horizontally-scrolling shooter game developed and published by Konami in February 2, 2004 for mobile phones, and was released on NTT DoCoMo's FOMA 900i line of phones in Japan and has been released in North America through Verizon Wireless as part of their Get It Now service.
- Gradius ReBirth (2008)
A Gradius title for WiiWare. It draws many elements from the MSX games and could be considered a heavy remake of those games.
- Gradius Arc (2009)
In March 2010, a Japanese trademark database update revealed a filing for this name, submitted by Konami.  The "Arc" portion of the name coincided with a pre-release name of the PlayStation Move. This was only coincidence, however, as Gradius Arc —Ginyoku no Densetsu— (Gradius Arc —Legend of the Silvery Wings—) was revealed on September 30, 2010, to be a tactical RPG for cell phones. 
- Gradius the Slot (2011)
Pachislot is coming in 2011.
- Salamander (1986)
Set in the same universe as Gradius. The game is noteworthy for a number of reasons. Most prominently, the game switches between horizontal and vertical stages, one of the first games of its kind. Also, Salamander was one of the first shoot'em ups to include cooperative gameplay.
- The first player ship is Gradius's own Vic Viper ship, while the second ship is the Lord British space destroyer (sometimes called the "RoadBritish").
- Unlike Gradius, Salamander uses a more conventional weapons system, with enemies leaving a wide-variety of distinct power-ups. The NES version of Salamander, called Life Force in North America (and marketed in that region as the "sequel" to the first Gradius), and the MSX port, used the more traditional power-up bar used in the Gradius series. There also exists an arcade game named Life Force that is identical to Salamander released in Japanese arcades the same year, except that a Gradius-style power-up bar is used instead of conventional power-up items, and the stages were recolored slightly and given some voiceovers to make the mission about travelling inside someone's body, rather than through space; stages took on names such as 'Kidney Zone' and 'Stomach'. An American release was also made, but it retained the original power-up system of Salamander, though it was renamed, rather confusingly, as Life Force.
- Salamander 2 (1996)
The follow-up to Salamander. Had several interesting features, such as the Option Shot, the ability to launch the Options as homing projectiles. After firing, an Option would revert to a smaller, less powerful unit called an Option Seed, which revolves around the ship firing the default shot. Weaponry includes Twin Laser, Ripple Laser, and standard Laser. Like its predecessor, Salamander 2 uses a power-up system, rather than the Life Meter. Upon acquiring a second power-up of the same type, your weapons are twice as powerful for a short duration (~10 seconds). The game features variations of previous Salamander bosses, such as the Golem and Tetran.
Is a off shoot of the Gradius series made in Japan and Europe for the MSX System and later for the Gameboy System.
- Parodius Series (1988-2010)
The Parodius series, started in 1988, is similar to Gradius, but with more cartoony settings. The name is a portmanteau of "parody" and "Gradius". Many of the mainstays of the Gradius series are included, albeit in a parodied format; this includes neon-colored core warships, effeminate moai, and large dancing women as bosses. Early games focused mainly on parodying Gradius games, but more recent games have poked fun at other Konami franchises, including Castlevania and Ganbare Goemon. The games offer a large number of different characters to use, each with different weapons. The characters consist of ones created for the series, such as Takosuke, and popular Konami characters like Pentarou and Upa. Vic Viper also appears in all titles.
- Otomedius (2007)
The game features magical-anime girl versions of Vic Viper and Lord British. Otomedius spoofs Gradius, but in a mecha musume-style approach. The name is a portmanteau of "otome" (a Japanese word meaning "maiden") and "Gradius".
- Otomedius Gorgeous (2008)
The Otomedius port for the Xbox 360 with a few upgrades.
- Otomedius Excellent (2011)
Is a Sequel of Otomedius Port Xbox 360.