Shoot 'em up

Shoot 'em ups are a fast-paced subgenre of action games. They are often called "shmups" or "STGs," which is a common abbreviation for shooting games in Japan.

In these games, a player controls a protagonist who must combat a large number of enemies. The player uses ranged weapons to attack from a distance while simultaneously dodging enemy fire. Success in this genre relies heavily on rapid reaction times and the ability to memorize complex enemy attack patterns. While some critics define the genre strictly by the use of spacecraft, others include characters on foot, such as robots or humans.

The mechanics of a shoot 'em up focus on constant movement and combat. Players typically control an avatar, such as a vehicle or spacecraft, that is under continuous attack. The primary goal is to shoot through waves of enemies to reach the end of a level, which often concludes with a boss battle. To survive, players can collect "power-ups." These items provide benefits like extra lives, health, shields, or upgraded weaponry. Many games do not use realistic physics to ensure the gameplay remains fast. For example, characters can change direction instantly without inertia, and projectiles often move at constant speeds in straight lines.

There are several distinct types of shoot 'em ups categorized by viewpoint and movement. Fixed shooters, such as Space Invaders (1978) or Galaxian (1979), restrict the player and enemies to a single screen. In these games, the player often moves along a single axis, like left and right or up and down. Multidirectional shooters, such as Asteroids (1979), allow for 360-degree movement. A specific version called a "twin-stick shooter" uses one joystick for movement and a second joystick for independent firing.

Another major category is the scrolling shooter. Vertically scrolling shooters present action from above as the screen moves up or down. Horizontally scrolling shooters use a side-on view that moves from left to right. Some of these games use an isometric point of view, which is a specific type of angled perspective. Run and gun games differ by featuring protagonists who move on foot. Games like Contra (1987) or Metal Slug (1996) often combine these shooting elements with platforming mechanics, such as the ability to jump.

Rail shooters offer a different experience by limiting the player's movement to a specific route. In these games, the action often moves "into the screen," providing a viewpoint from behind the player character. Some rail shooters utilize light guns for control, such as the series Time Crisis or The House of the Dead. There is also a subgenre known as "cute 'em ups." These games, like Fantasy Zone or Cotton, use brightly colored graphics and surreal, often bizarre settings. They stand out from more serious space-themed games through their unusual opponents and colorful aesthetics.

The history of the genre is deeply rooted in older forms of entertainment. The concept of shooting games predates video games, tracing back to 19th-century carnival shooting galleries. By the early 20th century, mechanical target shooting games appeared in English amusement arcades. The transition to digital gaming began with the mainframe game Spacewar! in 1962, developed at the Massachusetts Institute of Technology. However, the genre was truly established by the massive success of Space Invaders in 1978. This game created the general template that many subsequent arcade hits, such as Asteroids and Galaxian, would follow.

In the modern era, certain specialized subgenres have emerged to push the limits of the genre. "Bullet hell" games, also known as "manic shooters," feature overwhelming numbers of enemy projectiles.

In these games, players must navigate through complex "curtain fire" patterns. To make this possible, the "collision boxes" of the player characters are often much smaller than the actual visual sprites. Another niche is the "trance shooter," which uses abstract visuals and electronic music to create a reflex-based state. Recently, a "reverse bullet hell" or "bullet heaven" style has appeared, characterized by players collecting massive amounts of abilities that clutter the screen, as seen in the 2022 game Vampire Survivors.