Shoot 'em up

Shoot 'em ups are a subgenre of shooter game, in turn a type of action game. These games are usually viewed from a top-down or side-view perspective, and players must use ranged weapons to take action at a distance. The player's avatar is typically a vehicle or spacecraft under constant attack. Thus, the player's goal is to shoot as quickly as possible at anything that moves or threatens them to reach the end of the level with a boss battle.[10] In some games, the player's character can withstand some damage or a single hit will result in their destruction.[4] The main skills required in shoot 'em ups are fast reactions and memorising enemy attack patterns. Some games feature overwhelming numbers of enemy projectiles and the player has to memorise their patterns to survive. These games belong to one of the fastest-paced video game genres.

Large numbers of enemy characters programmed to behave in an easily predictable manner are typically featured.[11] These enemies may behave in a certain way dependent on their type, or attack in formations that the player can learn to predict. The basic gameplay tends to be straightforward with many variety of weapons.[4] Shoot 'em ups rarely have realistic physics. Characters can instantly change direction with no inertia, and projectiles move in a straight line at constant speeds.[10] The player's character can collect "power-ups" which may afford the character greater protection, an "extra life", health, shield, or upgraded weaponry.[12] Different weapons are often suited to different enemies, but these games seldom keep track of ammunition. As such, players tend to fire indiscriminately, and their weapons only damage legitimate targets.[10]

Spacewar!, an early computer game featuring shooting and spacecraft

The genre's exact origins are a matter of some confusion.[6] Video game journalist Brian Ashcraft pinpoints Spacewar! (one of the very earliest computer games) as the first shoot 'em up,[32] but the later Space Invaders is more frequently cited as the "first" or "original" in the genre.[6][7][33][34] Spacewar! was developed at the Massachusetts Institute of Technology in 1961, for the amusement of the developers; it was, however, remade four times as an arcade game in the early to mid-1970s. The game featured combat between two spacecraft.[35]

Space Invaders (1978) set the template for the shoot 'em up genre

However, it was not until 1978's seminal Space Invaders, created by Tomohiro Nishikado at Japan's Taito Corporation, that the shooter genre became prolific.[36] Space Invaders pitted the player against multiple enemies descending from the top of the screen at a constantly increasing rate of speed.[34] The game used alien creatures inspired by The War of the Worlds (by H. G. Wells) because the developers were unable to render the movement of aircraft; in turn, the aliens replaced human enemies because of moral concerns (regarding the portrayal of killing humans) on the part of Taito Corporation. As with subsequent shoot 'em ups of the time, the game was set in space as the available technology only permitted a black background. The game also introduced the idea of giving the player a number of "lives". It popularised a more interactive style of gameplay with the enemies responding to the player-controlled cannon's movement,[37] and it was the first video game to popularise the concept of achieving a high score,[38][39][40] being the first to save the player's score.[38] The aliens of Space Invaders return fire at the protagonist, making them the first arcade game targets to do so.[41] It set the template for the shoot 'em up genre,[42] and has influenced most shooting games released since then.[36]

In 1979, Namco's Galaxian—"the granddaddy of all top-down shooters", according to IGN—was released.[43] Its use of colour graphics and individualised antagonists were considered "strong evolutionary concepts" among space ship games.[44] That same year saw the release of SNK's debut shoot 'em up Ozma Wars, notable for being the first action game to feature a supply of energy, resembling a life bar, a mechanic that has now become common in the majority of modern action games.[45] It also featured vertically scrolling backgrounds and enemies.[46]

In 1981, Defender established scrolling in shoot 'em ups, offering horizontally extended levels. Unlike most later games in the genre, the player could move in either direction.[7] The game's use of scrolling helped remove design limitations associated with the screen,[47] and though the game's minimap feature had been introduced before, Defender integrated it into the gameplay in a more essential manner.[48] Konami's Scramble, released in 1981, is a side-scrolling shooter with forced scrolling. It was the first scrolling shooter to offer multiple, distinct levels.[7] Atari's Tempest, released in 1981, is one of the earliest tube shooters and an early attempt to incorporate a 3D perspective into shooter games.[49] Tempest ultimately went on to influence major rail shooters.[50][51]

Vertical scrolling shooters emerged around the same time. Namco's Xevious, released in 1983, is frequently cited as the first vertical scrolling shooter and, although it was in fact preceded by several other games of that type, it is considered one of the most influential.[7] Xevious is also the first to convincingly portray realistic landscapes as opposed to purely science fiction settings.[52] While Asteroids (1979) allowed the player to rotate the game's spacecraft,[53] 1982's highly acclaimed Robotron: 2084 was most influential on subsequent multi-directional shooters.[54][55]

Sega's Space Harrier, a rail shooter released in 1985, broke new ground graphically and its wide variety of settings across multiple levels gave players more to aim for than high scores.[56][57] 1985 also saw the release of Konami's Gradius, which gave the player greater control over the choice of weaponry, thus introducing another element of strategy.[7] The game also introduced the need for the player to memorise levels in order to achieve any measure of success.[58] Gradius, with its iconic protagonist, defined the side-scrolling shoot 'em up and spawned a series spanning several sequels.[59] The following year saw the emergence of one of Sega's forefront series with its game Fantasy Zone. The game received acclaim for its surreal graphics and setting and the protagonist, Opa-Opa, was for a time considered Sega's mascot.[60] The game borrowed Defender's device of allowing the player to control the direction of flight and along with the earlier TwinBee (1985), is an early archetype of the "cute 'em up" subgenre.[7][61] In 1986, Taito released KiKi KaiKai, an overhead multi-directional shooter. The game is notable for using a traditional fantasy setting in contrast to most shoot 'em up games filled with science fiction motifs.[62] R-Type, an acclaimed side-scrolling shoot 'em up, was released in 1987 by Irem, employing slower paced scrolling than usual, with difficult levels calling for methodical strategies.[3][63] 1990's Raiden was the beginning of another acclaimed and enduring series to emerge from this period.[64][65]

Shoot 'em ups such as SNK's Ikari Warriors (1986) featuring characters on foot, rather than spacecraft, became popular in the mid-1980s in the wake of action movies such as Rambo: First Blood Part II.[46] The origins of this type go back to Sheriff by Nintendo, released in 1979. Taito's Front Line (1982) established the upwards-scrolling formula later popularized by Commando, in 1985.[31] Commando also drew comparisons to Rambo[66] and indeed contemporary critics considered military themes and protagonists similar to Rambo or Schwarzenegger prerequisites for a shoot 'em up, as opposed to an action-adventure game.[31] In 1986, Arsys Software released WiBArm, a shooter that switched between a 2D side-scrolling view in outdoor areas to a fully 3D polygonal third-person perspective inside buildings, while bosses were fought in an arena-style 2D battle, with the game featuring a variety of weapons and equipment.[67] In 1987, Square's 3-D WorldRunner was an early stereoscopic 3-D shooter played from a third-person perspective,[68] followed later that year by its sequel JJ,[69] and the following year by Space Harrier 3-D which used the SegaScope 3-D shutter glasses.[70] That same year, Sega's Thunder Blade switched between both a top-down view and a third-person view, and introduced the use of force feedback, where the joystick vibrates.[71] Also in 1987, Konami created Contra as an coin-op arcade game that was particularly acclaimed for its multi-directional aiming and two player cooperative gameplay. However, by the early 1990s and the popularity of 16-bit consoles, the scrolling shooter genre was overcrowded, with developers struggling to make their games stand out (one exception being the inventive Gunstar Heroes, by Treasure).[72]

Japanese players at a shoot 'em up arcade in Akihabara, Tokyo. (2017)

A new type of shoot 'em up emerged in the early 1990s: variously termed "bullet hell", "manic shooters", "maniac shooters" and danmaku (弾幕, "barrage"), these games required the player to dodge overwhelming numbers of enemy projectiles and called for still more consistent reactions from players.[7][26] Bullet hell games arose from the need for 2D shoot 'em up developers to compete with the emerging popularity of 3D games: huge numbers of missiles on screen were intended to impress players.[26] Toaplan's Batsugun (1993) provided the prototypical template for this new breed,[73] with Cave (formed by former employees of Toaplan, including Batsugun's main creator Tsuneki Ikeda, after the latter company collapsed) inventing the type proper with 1995's DonPachi.[74] Bullet hell games marked another point where the shoot 'em up genre began to cater to more dedicated players.[7][26] Games such as Gradius had been more difficult than Space Invaders or Xevious,[58] but bullet hell games were yet more inward-looking and aimed at dedicated fans of the genre looking for greater challenges.[7][75] While shooter games featuring protagonists on foot largely moved to 3D-based genres, popular, long-running series such as Contra and Metal Slug continued to receive new sequels.[76][77][78] Rail shooters have rarely been released in the new millennium, with only Rez and Panzer Dragoon Orta achieving cult recognition.[15][57][79]

Treasure's shoot 'em up, Radiant Silvergun (1998), introduced an element of narrative to the genre. It was critically acclaimed for its refined design, though it was not released outside Japan and remains a much sought-after collector's item.[3][7][80][81] Its successor Ikaruga (2001) featured improved graphics and was again acclaimed as one of the best games in the genre. Both Radiant Silvergun and Ikaruga were later released on Xbox Live Arcade.[3][7][82] The Touhou Project series spans 23 years and 27 games as of 2019 and was listed in the Guinness World Records in October 2010 for being the "most prolific fan-made shooter series".[83] The genre has undergone something of a resurgence with the release of the Xbox 360, PlayStation 3 and Wii online services,[82] while in Japan arcade shoot 'em ups retain a deep-rooted niche popularity.[84] Geometry Wars: Retro Evolved was released on Xbox Live Arcade in 2005 and in particular stood out from the various re-releases and casual games available on the service.[85] The PC has also seen its share of dōjin shoot 'em ups like Crimzon Clover, Jamestown: Legend of the Lost Colony, Xenoslaive Overdrive, and the eXceed series. However, despite the genre's continued appeal to an enthusiastic niche of players, shoot 'em up developers are increasingly embattled financially by the power of home consoles and their attendant genres.[84][86]

• Ashcraft, Brian, (2008) Arcade Mania! The Turbo-Charged World of Japan's Game Centers, (Kodansha International)