Design Screenshot of River Raid (Atari 2600)The game is notable for providing a gigantic amount of fixed, non-random, repeating terrain despite tight limitations of available memory on its hardware platforms. The game program does not actually store the sequences of enemies and other objects; the terrain is dynamically generated algorithmically during gameplay using a linear feedback shift register with a fixed starting seed. A more highly randomised number generation system was used for enemy AI to make the game less predictable.  German controversyIn West Germany, River Raid was the first videogame to be banned for minors by being put on the Index by the Bundesprüfstelle für jugendgefährdende Schriften (Federal Department for Writings Harmful to Young Persons; today Bundesprüfstelle für jugendgefährdende Medien, Federal Department for Media Harmful to Young Persons in German). In the explanatory statement for indexation on December 19, 1984 it is written: "Minors are intended to delve into the role of an uncompromising fighter and agent of annihilation (...). It provides children with a paramilitaristic education (...). With older minors, playing leads (...) to physical cramps, anger, aggressiveness, erratic thinking (...) and headaches." (BPjS-Aktuell Heft 2/84)[this quote needs a citation] River Raid remained indexed as harmful to minors until 2002 when a publisher successfully lobbied to remove the game from the index in order to rerelease it in the Activision Anthology for the PlayStation 2. The anthology was rated "Free for all ages" by the "Unterhaltungssoftware Selbstkontrolle".  PortsAfter the initial Atari 2600 release, River Raid was ported to the following platforms: Atari 5200 Atari 8-bit ColecoVision Commodore 64 IBM PC IBM PCjr Intellivision MSX ZX Spectrum The Atari 2600 version of River Raid was made available on Microsoft's Game Room service for its Xbox 360 console and for Windows-based PCs in May 2010, and River Raid II in June 2010.