Multi-Phase
From Sega Retro
Multi-Phase is a term coined by Sega in 1979 to describe some of its arcade games.[1] "Multi-Phase" describes games having multiple "phases" as the player progresses, with more challenges added to the game after objectives are completed. For example, Sega's Head On (1979) introduces more enemy cars after all the dots are removed from the screen, forcing players to reassess their gameplay strategy.[2] Data East's Astro Fighter (1979), marketed by Sega as a "Multi-Phase" game in North America,[3] was a shoot 'em up that introduced multiple vertical scrolling levels with a boss battle at the end of each level. Earlier games like Space Invaders increase in difficulty by simply changing the speed of the enemies faster - the initial number of invaders is always the same, and the same pattern is always followed.
In some respects, "Multi-Phase games" are precursors to games which have different "levels" or "screens" - where gameplay can fundamentally change once tasks are completed. Sega trademarked the term and promoted the idea in North America, but this style of difficulty curve is not thought to have been invented by the company, nor was it exclusive to Sega products. David Rosen noted in 1979 that multi-phase arcade games existed in Japan at the time, but that Sega was the first to introduce this type of arcade game to North America.[1]
List of games
The following lists releases specifically designated by Sega as "multi-phase games".