A shoot-'em-up (also known as shmup) is a video game genre of shooter game in which the player controls a vehicle or character and fights large numbers of enemies with shooting attacks. The style of the game may range from cute to serious, from fantasy and science fiction to historic settings.
Shoot 'em ups originated in the arcades with Space Invaders usually being credited with the genre's birth. They peaked in popularity during the late 80s and early 90s, primarily as arcade and console titles. As the use of 3D graphics became more common in video games, the simplicity and arcade sensibilities of the genre slowly relegated their popularity to that of a niche. The genre remains most alive in Japan.
Rail shooters largely supplanted tube shooters with the rise of three dimensional gameplay. The player's viewpoint automatically turns and moves through the level as if player were attached to a railroad, hence the name of the subgenre. As the player is propelled forward, the player may have limited freedom of motion to dodge incoming attacks. A few notable rail shooters include Panzer Dragoon, Rez, and Star Fox.
Multidirectional shooters, also called arena shooters, allow freedom of movement and orientation in a two-dimensional environment. This may take place within a single-screen level such as Robotron: 2084, or allow players to navigate a larger playing field as the screen scrolls.
Examples of multidirectional shooters include Robotron: 2084, Time Pilot, Bosconian, Smash TV, Bangai-O, Geometry Wars, Everyday Shooter, Sinistar, Desert Strike, Crimsonland, Zone 66, plobb! and Super Stardust HD.
Examples of side-view run and guns include the Contra series, Metal Slug series, Abuse, Soldat, Liero Xtreme, Gunstar Heroes and Turrican (although the latter also has platform adventure elements and is generally less linear)
1980's Defender introduced a scrolling playfield to the shoot 'em up formula. It offered horizontally extended levels. Unlike most later games in the genre, this scrolling could go in either direction, and followed the player. This would be imitated by some later shoot 'em ups, notably Choplifter and Fantasy Zone. The following year, Konami introduced Scramble, a side scrolling shooter with forced scrolling. It was the first scrolling 'shooter to offer multiple, distinct levels, and laid the groundwork for Gradius. Konami has since retconned Scramble into the Gradius series to acknowledge this influence.
Vertical scrolling shooters developed around the same time. While early titles like Galaxian offered scrolling star fields, they were merely superficial. Sega's Borderline (1981) was a vertical shooter with primitive scrolling. In March of the next year, Data East released Mission-X and Zoar, the latter of which was licensed from Tago Electronics. Both games were very similar, with Zoar being the more developed of the two, with separate attacks for airborne and surface-based enemies. This same year Orca released Funky Bee, which offered a more straightforward approach. These games would be overshadowed at the end of the year, when Namco released Xevious, a title often credited with being the first vertically scrolling shooter.
1985 was a big year for shoot 'em ups, thanks to two major games. Tiger Heli was the first shooter from the developer Toaplan, who would become an important name in the genre over the decade to follow. Tiger Heli is perhaps most notable for introducing the "megabomb," a powerful limited use weapon, and one of the genre's most popular conventions. This same year saw the release of Konami's Gradius, another major innovator. Gradius introduced selectable weapons, as well as "options," small offensive pods that follow and aid the player. These conventions, would be frequently imitated in later shooters.
The following year, Compile would release their first shoot 'em up, Zanac, on the MSX computer and Famicom Disk System console. In the years to follow Compile would become one of the biggest developers of shoot 'em ups on consoles and computers. Sega also released Fantasy Zone, this same year, on their new 16-bit arcade hardware. The title would become very popular in Japan, and it introduced Sega's mascot Opa-opa. Taito also released Darius, the first in their flagship shooter series.
R-Type was introduced in 1987. The brain child of Irem, it became one of the major archetypes for side-scrolling shooters to follow, with vividly realized levels, and refined, methodical gameplay. Toaplan followed up Tiger Heli with Twin Cobra. This title introduced a system with a wandering power-up that changed colors to represent different weapons. This convention would become a staple of their games, as well as those of others.
Console and computer shooters became more common and were increasingly able to offer comparable experiences to their arcade counterparts. The PC Engine saw a whole slew of shooter titles released for it (in fact, PC Engine has by far the highest shooter/game ratio of any console in the postcrash gaming world) and the Thunder Force series brought arcade-style shooting to Japanese home computers and later the Sega Genesis. Games like Axelay and Bio-hazard Battle produced visuals and sounds worthy of their arcade contemporaries.
During this period, shoot 'em ups did not evolve a great deal. The genre remained vital while reusing variations on the same gameplay ideas that had proven themselves. In the early 90s new genres began to emerge, and the market diversified. Fighting games reached new-found popularity in the arcades with the release of Street Fighter II. Meanwhile, many console gamers were turning toward games that could provide longer playtime and in-depth narratives, and shoot 'em ups began to decline in popularity. In 1993, Compile shifted its focus away from shooters. In 1994, Toaplan closed its doors, and the genre lost one of its most devout supporters. For many this would serve as a signal that the Golden Age of shooters had ended.
The death of Toaplan would ultimately open more doors than it would close. Four companies would form from the ashes of Toaplan, and all remained even more devoted to the shooter genre than Toaplan. The first such company was Raizing. Raizing went as far as to continue to use Toaplan arcade hardware for their titles into the late 90s. Their first game was Mahou Daisakusen, the first title in their flagship trilogy.
The following year another company formed from ex-Toaplan staff. Cave premiered with Donpachi, a game which expanded on the design of Toaplan's final game Batsugun. Batsugun is considered by many to be the starting point for a new breed of shoot 'em up. These games would come to be called "danmaku" (lit. "bullet curtain") in Japan, and "manic" shooters in the West. These games are distinguished by high bullet counts, and a small collision zone (or "hit box") for the player.
Cave and Raizing would have something of a sibling rivalry. In 1996, Raizing released Battle Garegga, an homage to Taito's classic Gun Frontier. It pushed the manic style a level further, which, in turn, inspired Cave to put aside their reservations and produce the most manic shoot 'em up yet, Dodonpachi. Cave continued to carry the Toaplan torch, embedding the message "Toaplan Forever" in the high score tables. Their next game, Dangun Feveron, would be a pastiche to Toaplan as well, made to celebrate the tenth anniversary of Truxton.