Before the FPS games in computers and the side scrolling shoot-em-ups in video game consoles, video arcades have vertical scrolling shoot-em-ups. Most of these games have a tilted monitor, and they have a bird's eye view of a main character shooting bad guys. They lasted a long time, with Space Invaders, Asteroids, and Galaga in the 1970's to later games like SNK's Guerilla War to Capcom's Mercs in the 80's and 90's, and so on...

However, they don't translate well to home console systems in the 80's (NES and the Sega Master System) and the 16-bit consoles (SNES and the Sega Genesis) of the 90's because of the screens turned back to the horizontal rectangular orientation in TVs. That's where the side scrolling shoot-em-ups start to be popular in consoles.

A computer / video game where points are scored or progress is made by shooting projectiles at enemies. This is about the only common element between most shoot 'em ups, as the entity you control, and the style in which the world is navigated vary widely.

When the term is used on it's own by the gaming press or most gamers, it usually refers to games where you control a space ship, and where the screen scrolls either horizontally (eg, Gradius, R-Type), or vertically (eg, Gunhed, Xevious, Aleste, 1942), and also top down shoot 'em ups (eg, Ikari Warriors, Mercs), where you control a character viewed from above who can shoot and move freely in eight directions.

In recent years, the first person shoot 'em up (FPS) has become prevalant, and the traditional shoot 'em up has fallen to the wayside, only really retaining popularity in Japan and in the arcades. FPS games are viewed through the eyes of the character, and (usually) full freedom of movement is given. When the phrase "shoot 'em up" is used in the mainstream press, it more often than not refers to FPS games, unless it is in the context of classic gaming.

There is debate as to whether platform shoot 'em ups (eg, Metal Slug, Gunstar Heroes, Contra, Assault Suits Valken) should be filed under platformer or shoot 'em up, being simplistic platformers with a heavy emphasis on shooting stuff. The truth is that they fit comfortably into both genres.

There are also many examples of shoot `em ups that don't fit into the styles described above yet still fit the defining criterea. Though the one exception is light gun games, which are generally given their own category.

See also: shmups

Shoot `em up games are normally games that involve spaceships flying around and shooting the shit out of anything that gets in its way. The enemies normally range from other ships, to creatures, to animals, to just balls.

Shoot `em ups have been popular as they were cheap and easy arcade games to produce by game companies. They are inherently sprite-based games and simple to build as they only require a few sprites and motion controls. Though the numerous amounts of them are amazing.

There are at least a hundred games that fall into the shoot `em up category. A very select few of them are

• Centipede
• Galaga
• Gradius
• Life Force
• R-Type
• Tiger Heli
• Time Pilot

The differences between the games are usually based on the sprites of the games and the attacks. There is normally a control stick or control pad and two buttons. One button is almost always attack and the second button will either shoot as well, or select a special upgrade, or do a special attack. Each game is unique in the use of the second button.

The game's sprites do change to a great extent. Tiger Heli is a helicopter game where you shoot up buildings, where Galaga is where a ship shoots up space aliens. Centipede has a shooting gun that tries to kill Centipedes. Each game will usually use sprites that are unique to their game. In some games the stage moves down a corridor such as Tiger Heli and Gradius, while others like Galaga and Centipede are stationary installations.

Shoot `em ups tend not to have stories, but they are fun when you wish to just destroy other races. The games are usually just to shoot anything that you can see. The reasoning is usually because they are going to kill you. The games tend not to require thought but more likely to just use fast hand and eye coordination.

The shoot `em up games have faded to an extent when three-dimensional games started to gain popularity. The shoot `em ups are normally two-dimensional games. There are remnants of them in some games but only a few shoot `em ups are still being made.

Shoot `em ups are normally a fun diversion for a game, but due to their age and memory limits they tend to have only a couple hours of fun involved in them. More recent games tend to be harder. Gradius 3 for the Super NES has a much longer game with graphics that blow any old arcade games away.

Shoot `em ups now can normally be found in the corner of the arcades that is reserved for the "ancient" machines. They tend to be under used but private collectors can find them for a price.