Although not as famous as other coin-operated arcade games such as "Space Invaders" and "Pac-Man," "Scramble" is still considered a classic of the genre and a significant step forward in terms of game design. A shoot-em-up title set in space, "Scramble" was released in February 1981 by the Konami company. It was the first shoot-em-up title to feature multiple levels, among other innovations, and was successful in arcades.
The "Scramble" game features six levels, together representing a solar system. Players must maneuver a ship across each level, avoiding enemy missile attacks, or shooting the missiles in mid-flight to survive. Gameplay also involves monitoring the ship's fuel levels. Players must destroy fuel tanks on the ground to replenish the fuel needed to keep the ship going. Each level features a number of obstacles and is set in a different location. For example, the first level is set over hills, while the fourth is situated above a huge city, with enemies attacking from the tops of buildings. The final level consists of a base that players must destroy, with the game's difficulty rising each time this is accomplished.
"Scramble" was responsible for creating many of the conventions that horizontally-scrolling shoot-em-up video games followed in future years. For example, the layout and design of each level reflected the kind of environment that was being represented, something games such as "Space Invaders," with their identical level designs, couldn't accomplish. The concept of challenging the player to keep the ship fuelled also inspired similar game designs in later titles.
In the arcade, "Scramble" was housed inside a cabinet with a monitor at a 45-degree backward angle. Artwork adorned the sides of the cabinet, while the marquee that surrounded the monitor contained the game's logo. In terms of controls, the cabinet featured a joystick that could be rotated in four different directions, with two fire buttons on either side for both right- and left-handed play. The game's monitor had a 224- by 256-pixel resolution and allowed for up to 99 colors.
"Scramble" was the first title in what became Konami's "Gradius" sequence of similar shoot-em-up games, a series that later included "Salamander" and "Gradius Garden." Konami used the game engine it built for "Scramble" for other titles such as "Super Cobra," but since "Scramble" lacked any copyright protection, a wave of "Scramble" bootlegs later emerged, such as "Explorer," which played very similarly to "Scramble."
As well as appearing as an arcade game, "Scramble" is also available across a range of video game consoles, sometimes as part of classic title compilation packages. These include the Nintendo Game Boy Advance, the Sony PlayStation and the Nintendo DS, as well as computers such as the Sinclair ZX Spectrum, under other names including "Cavern Fighter."