Demon Attack

Demon Attack is a fixed shooter written by Rob Fulop for the Atari 2600 and published by Imagic in 1982. It was ported to the Intellivision, Magnavox Odyssey 2, Atari 8-bit family, VIC-20, Commodore 64, IBM PC (as a self-booting disk), TRS-80, IBM PCjr, and TRS-80 Color Computer. There is also a port for the TI-99/4A titled Super Demon Attack.
"Demon Attack" is supposedly based on the 1979 arcade shooter "Galaxian", though it closely resembles several waves from the 1980 arcade game "Phoenix". The similarities prompted a lawsuit from Atari, Inc., who had purchased the latter's home video game rights. Imagic settled out of court, and "Demon Attack" became Imagic's best-selling game as of 1983.
Gameplay.
Marooned on the ice planet Krybor, the player uses a laser cannon to destroy legions of demons that attack from above. Visually, the demons appear in waves similar to other space-themed shooters, but individually combine from the sides of the screen to the area above the player's cannon.
Each wave introduces new weapons with which the demons attack, such as long streaming lasers and laser clusters. Starting in Wave 5, demons also divide into two smaller, bird-like creatures that eventually attempt descent onto the player's cannon. Starting in Wave 9, the demons' shots follow directly beneath the monsters, making it difficult for the player to slip underneath to get in a direct shot.
Development.
The game was originally programmed to end after the 84th wave, as Fulop did not expect anyone to get so far. Two days after initial release however, the game was reported beaten. After the initial run of cartridges, Fulop went back and changed a single line of code so that the game never ends, but gets no harder.
The Odyssey 2 version was the first third-party game for the console.
Reception.
Jan Yarnot reviewed the Atari version of "Demon Attack" in "The Space Gamer" No. 53. Yarnot commented that "This game is interesting and enjoyable, and different enough from other cartridges to recommend it for all who must 'play Atari today.' The price is in line with other such programs and I think the fun of the game makes the price reasonable."
"Video" magazine reviewed the VCS version of "Demon Attack" in 1982, describing it as "quite simply excellent", and characterizing it as a "true coin-op-level program". Covering the game again in its 1982 Guide to Electronic Games, "Video" editors called the cartridge "a state-of-the-art invasion game" and suggested that its "slick graphics" represented "a quantum leap for the VCS", however "Video" reserved higher praise for the Intellivision version of the game which was described as "even more thrilling graphically than the original VCS edition". "Video Games" praised the Intellivision version of the game, stating that "while the VCS version is a very good TV-game, this one is even better". "Ahoy!" called the VIC-20 version "excellent ... it's a super-grabber type of twitch game, and good for a few long nights".
"Demon Attack" won the 1983 Arcade Award for "Best Videogame of the Year", with the judges commenting that the game had "turned out to be yardstick against which gamers measured the quality of each new cartridge during 1982".
Legacy.
A remake of the game has been announced for the Intellivision Amico.